Question

The base of an isosceles right triangle is 30 cm. Its area is

Options

•  225 cm²

•  225 \[\sqrt{3}\] cm² 

   

•  225 \[\sqrt{2}\] cm² 

   

• 450 cm²

Answer 1

\[\text{Let ABC be the right triangle in which}  \angle B = 90° . \]

\[\text{ Now, base = BC; perpendicular = AB; Hypotenuse = AC } \]

\[\text{ Now, BC = 30 cm } \left( \text{ given } \right)\]

\[\text{ Now, ∆ ABC is an isosceles right angled ∆ and we know that hypotenuse is the longest side of the right ∆ }m. \]

\[\text{ So, AB = BC = 30 cm } \]

\[\text{ area of ∆ ABC } = \frac{1}{2} \times\text{  base } \times \text{ height } \]

\[ = \frac{1}{2} \times BC \times AB\]

\[ = \frac{1}{2} \times 30 \times 30\]

\[ = 450  {cm}^2\]