The area of a triangle whose sides are of lengths 3 cm, 4 cm and 5 cm is :

Answer: Option B

Since 3² + 4² = 5²,
So it is a right-angled triangle with Base = 3 cm and Height = 4 cm
∴ Area :
$$\begin{array}{rl}& =\left(\frac{1}{2}\times 3\times 4\right)c{m}^2\\ & =6c{m}^2\end{array}$$