The perimeter of an isosceles triangle is 11 cm and its unequal side is 5 cm, then find its area ?

Asked by nisha_vini29 | 21st May, 2017, 11:29: PM

Expert Answer:

begin mathsize 14px style Let space each space side space of space isosceles space triangle space be space straight x space cm.
Then comma space perimeter space of space straight a space triangle equals straight x plus straight x plus 5
rightwards double arrow 11 equals straight x plus straight x plus 5
rightwards double arrow 11 equals 2 straight x plus 5
rightwards double arrow 2 straight x equals 6
rightwards double arrow straight x equals 3 space cm
Semi minus perimeter equals 11 over 2 equals 5.5 space cm
therefore space Area space of space triangle equals square root of 5.5 left parenthesis 5.5 minus 3 right parenthesis left parenthesis 5.5 minus 3 right parenthesis left parenthesis 5.5 minus 5 right parenthesis end root
equals square root of 5.5 cross times 2.5 cross times 2.5 cross times 0.5 end root
equals square root of 17.1875 end root
equals 4.15 space sq. space cm end style

Answered by Rashmi Khot | 22nd May, 2017, 09:06: AM