Question

Derive a formula to find the perimeter of an isosceles triangle in which one of the equal

sides is 3x + 2 and unequal side is 14

Answer 1

Given :

Length of one of the equal sides of an isosceles triangle = 3x+2

Then, length of the other equal side will also be = 3x+2

Length of the unequal side of this isosceles triangle = 14

Formula for finding the perimeter of an isosceles triangle :

`= \tt side + side + side`

A formula for finding the perimeter of this isosceles triangle :

`= \tt3x + 2 + 3x + 2 + 14`

Bringing all like terms together we get :

`=\tt 3x + 3x + 2 + 2 + 14`

`= \tt6x + 4 + 14`

`\color{plum}\tt = 6x + 18`

Thus, the formula = 6x+18

Therefore, a formula to find the perimeter of this isosceles triangle = 6x+18