Question

The perimeter of $\triangle A B C$ is $36\, cm$ and its in-radius is $8\, cm$. Then the area of the triangle is

• A. $144\, cm ^{2}$
• B. $124\, cm ^{2}$
• C. $164\, cm ^{2}$
• D. $104\, cm ^{2}$

Answer 1

Answer: (A)

In radius $(r)=\frac{\Delta}{S}$
$\Delta=(r \cdot s), \Delta \rightarrow$ Area, $S \rightarrow$ Semi-perimeter
$\Rightarrow \Delta=8 \times \frac{36}{2}=144\, cm ^{2}$