Question

If sides of a triangle are 3,5,7 then the area of that triangle is -

• A. $\sqrt{42.18}$
  
• B. $\sqrt{62.78}$
  
• C. $\sqrt{97.89}$
  
• D. $\sqrt{23.12}$
  

Answer 1

The correct option is A $\sqrt{42.18}$


We know the area of a triangle can be calculated using its sides through Heron's formula
$\sqrt{s(s-a)(s-b)(s-c)}$
Where "s" is the semiperimeter of the triangle.
And a, b, c are the sides of it.
So, $s=\frac{3+5+7}{2}=7.5$
And Area = $\sqrt{7.5(7.5-3)(7.5-5)(7.5-7)}$
$=\sqrt{42.18}$