Question

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

• A. $225c{m}^2$
  
• B. $225\sqrt{3}c{m}^2$
  
• C. $225\sqrt{2}c{m}^2$
  
• D. $450c{m}^2$

Answer 1

The correct option is A

$225c{m}^2$

Now in right $\Delta ABC$
$A{B}^2+A{C}^2=B{C}^2\Rightarrow x^2+x^2=(30{)}^2$
= $2x^2=900\Rightarrow x^2=\frac{900}{2}$