O is the centre of a circle of radius 10 cm. P is a point outside the circle and PQ is a tangent to the circle. What is the length (in cm) of PQ if the length OP is 26 cm?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 24
Calculations:
Using pythagoras theorem : (Hypotenuse)2 = Base2 + perpendicular2
PQ2 = OP2 - OQ2
⇒ PQ2 = 262 - 102
⇒ PQ2 = 676 - 100
⇒ PQ2 = 576
⇒ PQ = 24 cm