Question

In ΔABC, AB=3, BC=4, AC=5, then the radius of the circle touching all the three sides is ......,select a proper option (a), (b), (c) or (d) from given options so that the statement becomes correct.
(a) 2
(b) 1
(c) 4
(d) 3

Answer 1

Option ( b ) is correct .

Explanation :

In ∆ABC ,

AB = c = 3 cm ,

BC = a = 4 cm,

CA = b = 5 cm

We know that ,

( 3 , 4 , 5 ) is a Pythagorean

Triplet .

Therefore ,

∆ABC is a right angled triangle.

CA = b is a hypotenuse .

Now ,

Radius the incircle (r)=( c+a-b)/2

=> r = ( 3 + 4 - 5 )/2

=> r = 2/2 = 1 cm

••••

Answer 2

Answer:

option b is correct answer