Question

If sides of a right-angled triangle are in ratio 3:4:5 and its perimeter is 48 cm, then value of area in $c{m}^2$ is ___.

• A. 30
• B. 45
• C. 96
• D. 135

Answer 1

The correct option is C 96

Let the sides of the triangle be 3y, 4y and 5y.
Given Perimeter = 48 cm
Hence 3y + 4y + 5y = 48
12y = 48
y = 4
Sides are 12, 16 and 20 in cm
Here side of length 12 cm and 16 cm are perpendicular sides and side of length 20 cm is the hypotenuse.

Area of right angled triangle
= $\frac{1}{2}$$\times$(Product of perpendicular sides)
= $\frac{1}{2}$$\times$(12$\times$16) = 96 $c{m}^2$