Question

The sides of a triangle are in the ratio 3:4:5.If its perimeter is 36cm,area is

Answer 1

Answer:

54cm²

Step-by-step explanation:

It is given that the sides of a triangle are in the ratio 3 : 4 : 5.

Let the length of sides are 3x, 4x and 5x.

It's perimeter is 36 cm.

⇒  3x + 4x +5x = 36

or, 12x = 36

∴ x = 3

⇒3x = 3*3 = 9

⇒4x = 4*3 = 12

⇒5x = 5*3 = 15

The value of x is 3. The length of sides are 9, 12, 15.

It is an right angled triangle because the sum of squares of two smaller sides is equal to the square of larger sides.

9² + 12² = 15²

Here, the length of hypotenuse is 15 cm.

The area of triangle is

⇒ A = 1/2 × base × height

       = 1/2 × 9 × 12

       = 54cm²

Therefore the area of triangle is 54 cm².