Question

Area of an issoceles triangle is 12 cm square find it's base if the length of it's equal sides is 5 cm​

Answer 1

Step-by-step explanation:

Following are the available values:

Base: ?

Area: 12 cm sq

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

Answer 2

Hello ❤️

Let the base be b cms

Then the semi perimeter s= (b+5+5)=(b-10)/2

By heron's formula area of the triangle= rt(s(s-a)(s-b)(s-c)

12=rt {b+10/2(b+10)/2-b)}

{(b+10)/2-5)(b+10/2-5)}

Squaring 144=(b+10)/2(10-2)/2(b/2)(b/2)

Simplifying we get b^4-100^2+2304=0

Which yields b=6 or 8

Hence base is 6 or 8..

Hope it will help you ☺️