Question

from an external point p two tangents PQ and PR are drawn to a circle of radius 4cm with centre O. If QPR = 90`, then length of PQ is

Answer 1

The length of PQ is 4 cm .

• Tangent of a circle make 90 degree with respect to center .
• Let center of the circle be O .  Join PQORP to form a quadrilateral .
• Three angles of the quadrilateral are  90 degree then the fourth angle at center will be of 90 also .
• Two adjacent side that is QO and RO are equal . Thus the quadrilateral is a square .
• The length of PQ will be 4 cm .