The length of the tangent drawn to a circle with radius 7 cm from a point 25 cm away from the centre is = ___ cm.
∠ABO= 90∘ (point of contact)
Using Pythagoras theorem
AO2= AB2+ BO2
252= AB2+ 72
252 - 72 = AB2
24= AB
length of the tangent = 24 cm