Question

Find the area of isosceles triangle if each equal side of triangle is 14 cm and the perimeter is 40 cm.

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Answer 1

Answer:

Given :

$\textsf{Perimeter of the isosceles triangle = 40 cm}$

$\textsf{Equal sides are = 14 cm}$

To find :

$\textsf{Area of the isoseles triangle}$

Concept :

To find the area of the isosceles triangle first find the length of the third side of the isoseles triangle.

So , third side of the isosceles triangle -:

Let the third side be x .

$\sf\implies{x+14cm+14cm=40cm}$

$\sf\implies{x+28cm=40cm}$

$\sf\implies{x=40cm-28cm}$

$\sf\implies{x=12cm}$

So , the third side of the isosceles triangle is 12 cm .

And to find the area of the triangle use this formula -:

$\sf\boxed{A=\dfrac{H\:\times\:B}{2}}$

Here ,

A = Area of the triangle

H = Height of the triangle

B = Base of the triangle

And the height is 14 cm and the base is 12 cm .

Solution :

$\sf\implies{A=\dfrac{14cm\times12cm}{2}}$

$\sf\implies{A=\dfrac{168cm}{2}}$

$\sf\implies{A=84\:cm}$

So , the area of the isosceles triangle is 84 cm .

Answer :

Area of the isosceles triangle = 84 cm