Question

The base of an isoceles triangle measures 80 cm and its area is 360 cm^2. Find the perimeter of the triangle.

Answer 1

perimeter is 162cm...

Answer 2

Let us assume the equal sides to be x.

Given that base=80 cm.
 
=> Height of the isosceles triangle=$\sqrt{x^{2}-40^{2}}$ (using pythagoras theorem)

So, area=$\frac{1}{2}bh$

360=$\frac{1}{2}*80*<span>\sqrt{x^{2}-40^{2}}$ 

9=$\sqrt{x^{2}-40^{2}}$

81=${x^{2}-40^{2}}$

x^{2}=1681

x=41cm

=> Perimeter=41+41+80=162cm.