Question

The perimeter of a triangle is $36$ cm and its sides are in the ratio $a:b:c=3:4:5$ then a, b, c are respectively :

• A. $9cm,15cm,12cm$
• B. $15cm,12cm,9cm$
• C. $12cm,9cm,15cm$
• D. $9cm,12cm,15cm$

Answer 1

The correct option is D $9cm,12cm,15cm$

Let the sides of the triangle are $3x,4x,5x$

Now , perimeter of triangle $=3x+4x+5x=12x$

$36=12x$

$x=3$

Sides of triangle are :

$3\times 3=9cm4\times 3=12cm5\times 3=15cm$