Question

Q1. The hypotenuse of a right angled triangle is 5cm and one of its side is 4 cm. What is the
perimeter of the triangle?
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Answer 1

Given:

A right angled triangle with

• Hypotenuse = 5 cm
• One side = 4 cm

To Find:

The perimeter

How To Find:

To find the perimeter we will first find the third side of the right angled triangle and add the side to get the perimeter of the right angled triangle.

Solution:

• Finding the third or other side

Using the formula,

⇒ a² = b² + c²

Substitute its values,

⇒ 5² = 4² + c²

Multiply,

⇒ 25 = 16 + c²

Take 16 to LHS,

⇒ 25 - 16 = c²

Subtract 16 from 25,

⇒ 9 = c²

Now, find the value of c

⇒ $\sf{\sqrt{9} = c}$

Now, do the calculation,

⇒ 3 = c

• Finding the perimeter

Using the formula,

⇒ Perimeter of triangle = Sum of all sides

Substitute the value,

⇒ Perimeter = 5 cm + 4 cm + 3 cm

Add the sides,

⇒ Perimeter = 12 cm.

∴ So, the perimeter of a right angled triangled is 12 cm.