Question : The radius of the incircle of a triangle whose sides are 9 cm, 12 cm, and 15 cm is:
Option 1: 9 cm
Option 2: 13 cm
Option 3: 3 cm
Option 4: 6 cm
Correct Answer: 3 cm
Solution :
To find: The radius of the incircle of a triangle whose sides are 9 cm, 12 cm and 15 cm.
Since, $9^2+12^2=81+144=225=15^2$
So, this is a right-angled triangle.
Let $p,b,$ and $h$ be Perpendicular, Base and Hypotenuse of the triangle, respectively.
We know the radius of the incircle of a right-angled triangle,
= $\frac{p+b-h}{2}$
= $\frac{9+12-15}{2}$
= $\frac{6}{2}$
= 3 cm
Hence, the correct answer is 3 cm.
Related Questions
Know More about
Staff Selection Commission Multi Tasking ...
Application | Cutoff | Selection Process | Preparation Tips | Eligibility | Exam Pattern | Admit Card
Get Updates Brochure
Your Staff Selection Commission Multi Tasking Staff Exam brochure has been successfully mailed to your registered email id “”.
