Question

Find the perimeter of the triangle below. Then, explain the steps you used to find the perimeter

Answer 1

The perimeter of the triangle = 60 cm

Solution:

The given triangle is a right triangle.

Base of the triangle = 15 cm

Hypotenuse = 25 cm

Let the unknown side of the triangle be x.

Using Pythagoras theorem,

In right triangle, square of the hypotenuse is equal to the sum of the squares of the other two sides.

$x^2+15^2=25^2$

$x^2+225=625$

Subtract 225 from both sides,

$x^2=400$

Taking square root on both sides, we get

x = 20

The unknown side of the triangle is 20 cm.

The perimeter of the triangle = Sum of the sides of the triangle

                                                 = 15 cm + 25 cm + 20 cm

                                                 = 60 cm

The perimeter of the triangle = 60 cm