Shaalaa.com | Circles (Tangent Properties Part 1)
Radius of a sector of a circle is 21 cm. If length of arc of that sector is 55 cm, find the area of the sector.
Two circles intersect each other at points C and D. Their common tangent AB touches the circles at point A and B. Prove that :
∠ ADB + ∠ ACB = 180°