Question

find the of an isosceles triangle each of whose equal sides measure 13cm and whose base measures 20cm

Answer 1

area of the isosceles triangle is 10√69 cm²

Answer 2

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.)