CBSE Class 10 Maths Triangles

equilateral triangle ABC , D is a point on side BC such that 3BD = BC. Prove that 9AD2 = 7AB2.

Question
 If A is the area of right triangle and b is one of the sides containing the right angle,then prove that the length of the altitude on the hypotenuse is 2Ab/√(b^4+4A^2)
 The height of a moving truck is 8 m. The distance from the bottom edge of the ramp on the ground to the truck is 15 m. What is the length of the ramp?
 In an equilateral triangle AD is the altitude drawn from A on side BC. Prove that 3AB^{2} =4AD^{2}
 The area of a right triangle is 210 sq cm. If the smallest side is 12 cm, what is the hypotenuse?
 What is the value of a if a, a1,a+8 are the lengths of the sides of a right triangle where a is a natural number?
 In quadrilateral ABCD, If AD^{2} = AB^{2} + BC^{2} + CD^{2}. Prove that
 The diagonals AC and BD of a rhombus ABCD are of length 6 cm and 8 cm respectively. What is the perimeter of the rhombus?
 Prove that if for a right triangle the sides containing the right angle have even numbers as their lengths, then the third side can"t be an odd number.