Question

Find the area of an isosceles triangle each of whose equal sides measures 13 cm and whose base measures 20 cm.

Answer 1

We have three sides- 13cm,13cm and 20cm, you can easily find the perimeter by using heron's formula

First of all- we need to get the semi-perimeter
s=a+b+c/2=13+13+20/2
=46/2=23
now, put the heron's formula i.e. √s(s-a)(s-b)(s-c)
=√23(23-13)(23-13)(23-20)
=√23*10*10*3
=√23*2*5*2*5*3
=10√23*3
=10√69
=83.07cm^2 (approx.)