Question

A circle touches two of the smaller sides of a DABC (a < b < c) and has its centre on the greatest side. Then the radius of the circle is –

• A.
• B.
• C.
• D. None of these

Answer 1

Answer: (C)

Answer 2

Let O be the centre and r be the radius of the circle.

Then ar. (DBOC) + ar. (DAOC) = ar. (DABC)

Ž (a + b) $\frac { \mathrm { r } } { 2 }$ = $\sqrt { s ( s - a ) ( s - b ) ( s - c ) }$

Ž r = $\frac { 2 \sqrt { s ( s - a ) ( s - b ) ( s - c ) } } { a + b }$, r = $\frac { 2 \Delta } { a + b }$

where .