Question

The sides of a triangle are 21 cm, 17 cm and 10 cm. Find it's area.

Answer 1

We use Heron's formula to solve this problem.
Let a,b and c represent 3 sides of the triangle, such that a = 21 cm, b = 17 cm and c = 10 cm.
$\therefore$ a + b + c = 21 + 17 + 10 cm = 48 cm
Semi perimeter, s = ( a + b + c)/2 = 48/2 cm = 24 cm
Area of the triangle :-
$\sqrt{s(s-a)(s-b)(s-c)}=\sqrt{24(24-21)(24-17)(24-10)}c{m}^2=\sqrt{24\times 3\times 7\times 14}=\sqrt{2\times 2\times 3\times 2\times 3\times 7\times 2}=2\times 2\times 3\times 7c{m}^2=84c{m}^2$