Question

If the sides of a triangle are in the ratio 7:8:9 and its smallest side is 14 cm, find the semi perimeter of the triangle. [2 MARKS]

Answer 1

Concept : 0.5 Mark
Application : 0.5 Mark
Calculation : 1 Mark

Perimeter of a triangle = a +b +c

Since the sides are in the ratio 7:8:9 and the smallest side is 14 cm

$\Rightarrow$ 7x = 14
$\Rightarrow$ x = 2
$\Rightarrow$ Other two sides are = $8\times 2$ cm and $9\times 2$ cm = 16 cm and 18 cm

Therefore, semi perimeter of the triangle = $\frac{a+b+c}{2}$ = $\frac{14+16+18}{2}$ = 24 cm