Question

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

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.)

Hope i helped you!!

Answer 2

Step-by-step explanation:

semiperimeter = 1/2× (13×13 ×20)

1/2×46=23

area = root s(s-a) (s-b) ( s-c)

= root 23×10×10×3

= 23×5×2×5×2×3

= 10 root (23×3)

= 10 root 69

= 83.06 cm²