Question

Draw a circle of center O and radius 3cm. Draw tangents PA and PB from external point P to the circle,such that PA=PB=2√10

Answer 1

Drawn , a required circle

•Given,

radius = 3 cm

PA = PB = 2√10 cm

•In triangle OAP

•By Pythagoras theorem

OA² + PA² = OP²

3² + (2√10)² = OP²

9+40 = OP²

OP² = 49

OP = 7 cm

• Now draw a point P 7cm away from the circle and join OP

• Now from point P make two lines make two tangents.

• Tangents will measure 2√10cm