Question

In a right triangle abc right angled at b bc is 15cm and ab is 8 cm. a circle is inscribed in triangle abc. find radius of circle

Answer 1

Answer:

Answer

Correct option is

C

3cm

Using Pythagoras theorem in △ABC

(AB)

2

+(BC)

2

=(AC)

2

(15)

2

+(8)

2

=(AC)

2

⇒(AC)

2

=225+64=289

⇒AC=17cm

Now inradius r=

s

Δ

where Δ is the area of triangle and s is semi perimeter.

Δ=

2

1

×8×15=60

s=

2

8+15+17

=

2

40

=20

⇒r=

s

Δ

=

20

60

=3cm