Question

A triangle has sides of lengths 3centimetrs 4 centimetre 5centimetre.what is the area of the circle inscribed in the triangle?

Answer 1

Sides are 3, 4 and 5 .

Thus, it is right angle triangle.

Since 5^2 = 3^2 + 4^2

Therefore, Area = 1/2 × 3 × 4 = 6

We have to find in-radius

Therefore, area of triangle = S × r

where S=semi-perimeter and r= in-radius

Now,

S=semi-perimeter = 5+4+3 /2 = 6

Thus , 6 =2πr

and hence r=in-radius= 3