Question 130

C and C are two concentric circles with centres at 0. Their radii are 12 cm. and 3 cm. respectively. B and C are the points of contact of two tangents drawn to C2 from a point A lying on the circle C1. Then the area of the quadrilateral ABOC is

AB = AC = tangents from the same point

OB = OC = 3 and OA = 12

$$\angle$$ABO = 90

=> AB = $$\sqrt{12^2 - 3^2} = 3\sqrt{15}$$

Now, area of $$\triangle$$OAB = $$\frac{1}{2}$$ OB * AB

= $$\frac{1}{2} * 3 * 3\sqrt{15} = \frac{9\sqrt{15}}{2}$$

$$\therefore$$ area of OABC = $$9\sqrt{15}$$ sq. cm

Need AI Help?

Video Solution

video

Create a FREE account and get:

  • Free SSC Study Material - 18000 Questions
  • 230+ SSC previous papers with solutions PDF
  • 100+ SSC Online Tests for Free

Join CAT 2026 course by 5-Time CAT 100%iler

Crack CAT 2026 & Other Exams with Cracku!

Ask AI

Ask our AI anything

AI can make mistakes. Please verify important information.