2024 · Q94
A circle is inscribed in a triangle ABC right-angled at B. If AB = 5 cm and BC = 12 cm, then what is the radius of the circle?
Elementary MathematicsCircles
- A1 cm
- B1.5 cm
- C2 cm
- D2.5 cm
Explanation
The triangle 5-12-13 is right-angled at B. For a right triangle the inradius is (a+b−c)/2 where c is the hypotenuse. Here r = (5+12−13)/2 = 4/2 = 2 cm — option C.