Question

if the area of an isosceles triangle is 60cm then it's two equal sides are 13 cm find the base​

Answer 1

Answer:

Draw altitude AD.

Ar(ΔABC)=60cm2

12AD×BC=60

bh=60 where h is height and b is CD

 

By Pythagoras theorem

AC2=b2+h2

b2+h2=132=169

(b+h)2=b2+h2+2bh=169+2×60=289

b+h=289−−−√=17cm …equation 1

(b−h)2=b2+h2−2bh=169−120=49

b−h=49−−√=±7cm …equation 2

equation 1 + equation2

2b=±7+17=24cm,10cm

As b=CD so 2b=BC=base

Thus, base = 24cm or 10 cm

pls mark brainliest