Q. Two circles with centres (2, 3) and (5, 6) cut orthogonally. If radius of both circles are equal, then radius is equal to
A) 1
B) 2
C) 3
D) 4
Explanation
(c)
Using the result $\left( C_{1}C_{2} \right)^{2} = r_{1}^{2} + r_{2}^{2}$, we get
$(2 - 5)^{2} + (3 - 6)^{2} = r^{2} + r^{2}$
$\Rightarrow 2r^{2} = 18$
$\Rightarrow r^{2} = 9$
$\Rightarrow r = 3$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.