Question

The area of an isosceles triangle is 12cm2 if one of its equal side is 5 cm find its base

Answer 1

side 1: 5 cm

The formula of area is :

1/2 X base X height

- let the base be 2b and height be h.

- bXh= 12

- h= 12/b

- use Pythagoras theorem:

b²+h²= 5²

so b²+ 12²/b²= 25

so next your equation will be: b( power 4) - 25b²+144=0

So next (b + 4)(b – 4)(b + 3)(b – 3) = 0

Neglecting the negative values, b could be 3 giving h = 4

or b could be 4 giving h = 3

This means the whole base could be 6 and the height is 4

or the whole base could be 8 and the height is 3