# Angle Sum Property Of A Triangle Free Doubts and Solutions

### CBSE - IX - Mathematics - Lines and Angles

## In triangle ABC, AE is the bisector of angle BAC and AD is perpendicular to BC. Show that angle DAE is equal to 1/2(angle C- angle B).

**mandaokar**26th February 2018, 8:44 PM

### CBSE - IX - Mathematics - Lines and Angles

## Show that equiangular triangle is also equilateral ?

**Vikas**13th July 2017, 10:29 AM

### CBSE - IX - Mathematics - Lines and Angles

## hi sir ho do i ask my question with the help of a diagram

**Amanjot**8th August 2016, 6:47 PM

### CBSE - IX - Mathematics - Lines and Angles

## My question is that.......please can you explain me stepwise the answer of exercise 6.3 ques no.-6

**Rishi_2109**28th July 2016, 9:25 PM

### CBSE - IX - Mathematics - Lines and Angles

## prove that the sum of angles of a triangle is 180.Using this find all the angles of a triangle if the angles are in the ratio 1:2:3.
Give your view how the measure of angles useful in making furniture?
Is accuracy necessary in measurements?

**kumarasia**22nd September 2014, 8:47 AM

### CBSE - IX - Mathematics - Lines and Angles

## <div>Bisectors of angle B and Cof a triangle intersect each other at point 'O'.Prove thatangle BOC=</div> <div>90<img class="Wirisformula" src="https://images.topperlearning.com/topper/tinymce/integration/showimage.php?formula=b11d7e43055ab38e82de105768df5315.png" alt="ring operator" align="middle" /> +1/2<img class="Wirisformula" src="https://images.topperlearning.com/topper/tinymce/integration/showimage.php?formula=10760cd90092037cd4f09dde6a7d7bb7.png" alt="angle" align="middle" />A</div>

**Delin**31st August 2014, 2:46 PM

### CBSE - IX - Mathematics - Lines and Angles

## <div>Bisectors of angle B and Cof a triangle intersect each other at point 'O'.Prove thatangle BOC=</div> <div>90<img class="Wirisformula" src="https://images.topperlearning.com/topper/tinymce/integration/showimage.php?formula=b11d7e43055ab38e82de105768df5315.png" alt="ring operator" align="middle" /> +1/2<img class="Wirisformula" src="https://images.topperlearning.com/topper/tinymce/integration/showimage.php?formula=10760cd90092037cd4f09dde6a7d7bb7.png" alt="angle" align="middle" />a</div>

**Delin**31st August 2014, 2:46 PM

### CBSE - IX - Mathematics - Lines and Angles

## how does angle a meets angle b and c

**snmanjunath62**6th July 2014, 2:39 PM

### CBSE - IX - Mathematics - Lines and Angles

## Ajay was asked to find the sum of the four angles of a quadrilateral. He found the sum of the four angles as 270o by giving the reasoning as follows: Sum of the three angles of a traingle [made up of three sides] = 2 right angles = (3-1) right angles. So, sum of the four angles of quadrilateral [made up of four sides] = (4 – 1) right angles = 3 right angles = 270o His classmate Anju pointed out that the sum obtained is incorrect and found the correct sum. Ajay accepted his mistake and thanked Anju for the same. Write the correct solution. What value is depicted from this action?

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## Find x and y in the given figure.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## In figure, TQ and TR are the bisectors of Q and R respectively, QPR = 80°, PRT = 30°.Determine TQR and QTR.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## In the given figure, Prove that x = a + b + c.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## In ΔXYZ, YO and ZO are the bisectors of ÐXYZ and ÐXZY respectively of ΔXYZ. If X = 62°, XYZ = 54°, then find ÐOZY.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## In fig., find the value of x.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## In figure, the side QR of PQR is produced to a point S. If the bisectors of PQR and PRS meet at point T, then prove that QTR = QPR.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## Prove that the sum of the angles of a triangle is 1800.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## In figure, if line segment AB intersects CD at O such that OAD = 800, ODA= 500 and OCB= 400, then find OBC.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## In fig., if QTPR, TQR = 40° and SPR = 30° find the value of x and y.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## In fig., find the value of x.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## In figure, and bisector of meets BC at a point D. Find the value of

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## The sides BA and DC of a quadrilateral ABCD are produced as shown in fig. Show that x + y = a + b.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## In fig., the side BC of ABC is produced to D, the bisector of BAC intersects the side BC at E. Prove that ABC + ACD = 2AEC.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## An angle is equal to five times of its complement. Find the measure of the angle.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## Prove that an equilateral triangle can be constructed on any given line segment.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## In fig., in PQR, right angled at P. PS is perpendicular to QR. Prove that QPS = PRQ.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## If the bisectors of the angles ABC and ACB of a triangle ABC meet at point O then prove that BOC = 90o + .

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## In figure, if PQ||RS, ACS = 117o then find (x - y).

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## In figure the side QR of PQR is produce to a point S. If the bisectors of PQR and PRS meet at T, then prove that QTR =.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## Prove that each angle of an equilateral triangle is 60o.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## If the angles of a triangle are in the ratio 1:2:3 then find the measure of angles.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## In figure find the value of QRP when QP||TR.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## Prove that sum of the exterior angle of a triangle is 360o.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## In figure, if PQ||RS, then find SRO.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## Two lines AB, CD are intersected by a transversal EF. What is the measure of the angle between the bisectors of the co interior angles formed due to these lines?

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## The angles of a triangle are in the ratio 2:3:5. If the longest and the shortest sides are 10 and 6 cm respectively, what is the third side?

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## Prove that the sum of all the interior angles of a pentagon is 540o.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## Prove that the angle between the interior bisectors of any two angles is equal to 90 degrees plus half the third angle.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## In the figure show that A+ B+C +D+ E+F = 360o.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## If the sides of a triangle are produced in order, prove that the sum of the exterior angles so formed is equal to four right angles.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## In the figure ACCE and A:B :C = 3: 2: 1, find the value of ECD

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## A triangle LMN is right angled at L. If LO MN, prove that MLO = LNM.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## Calculate the value of x in the given figure.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## In triangle PQR, if P - Q = 42o and Q - R = 21o, find P, Q and R.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## In triangle ABC, if A + B = 108o and B +C = 130o, find A, B and. C

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## The sides AB and AC of a triangle are produced to D and E respectively. The bisectors of CBD and BCE meet at O. If A = 40o, find BOC.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## If the bisectors of B and C of triangle of a ABC intersect at O, then prove that BOC = 90o + .

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## Can a triangle have (i) Two right angles? (ii) All angles less than 60o? (iii) All angles equal to 60o? (iv)Two acute angles? Justify your statement in each case.

**Topperlearning User**4th June 2014, 1:23 PM

### CBSE - IX - Mathematics - Lines and Angles

## The exterior angles obtained on producing the base of a triangle both ways are 100° and 120° respectively. Find all the angles.

**Topperlearning User**5th December 2013, 2:04 AM

### CBSE - IX - Mathematics - Lines and Angles

## In fig., BO and CO are bisectors of DBC and ECB respectively. If BAC = 50o and ABC = 60o then find the measure of BOC.

**Topperlearning User**5th December 2013, 1:58 AM

### CBSE - IX - Mathematics - Lines and Angles

## In figure, if AB||CD, FAE = 90o and AFE = 40o then find ECD.

**Topperlearning User**5th December 2013, 1:56 AM

### CBSE - IX - Mathematics - Lines and Angles

## In figure, BP AC, PBC = 25o and DAC = 30o. Find the value of x.

**Topperlearning User**5th December 2013, 1:11 AM