Question

The sides of a triangle are in the ratio 3:2:4. If the perimeter of the triangle is 36 cm, then the length of its longest side is ___ cm.

• A. 12 cm
• B. 16 cm
• C. 18 cm
• D. 20 cm

Answer 1

The correct option is B

16 cm

Let the sides be 3x, 2x and 4x.

Sum of all sides = Perimeter = 36 cm

$\Rightarrow$ 3x + 2x + 4x = 36

$\Rightarrow$ 9x = 36

$\Rightarrow$ x = $\frac{36}{9}$ = 4 cm

$\therefore$ Length of the longest side = 4x = 4$\times$4 = 16 cm