Question

ABC is a right angled triangle right angled at B . A circle with centre O inscribed in the triangle . AB=6CM BC=8CM . Find the radius r of the circle

Answer 1

Radius = 2 cm.

Step by step explanation:

By the Pythagoras theorem the third side of the triangle

= sqrt (6^2 + 8^2)cm = sqrt100 = 10cm.

The formula for the radius of the circle is

r = sqrt [ (s - a)(s-b)(s-c)/ s ] where a,b,c are side lengths and s = the semi perimeter.

Here s = ( 6+8+10) / 2 = 12

So the radius r

= sqrt [ (12-6)(12-8)(12-10)/ 12 ]

= sqrt 4

= 2 (answer).