Login/Sign Up
Home » A point P is at a distance 13 cm from the center C of a circle and PT is a tangent to the given circle. If PT = 12 cm, find the radius of the circle.
A point P is at a distance 13 cm from the center C of a circle and PT is a tangent to the given circle. If PT = 12 cm, find the radius of the circle.
CBSE | Circles | Class 10 | Exercise 1 | Maths | ML Aggarwal
A point P is at a distance 13 cm from the center C of a circle and PT is a tangent to the given circle. If PT = 12 cm, find the radius of the circle.

Solution:

CT is the radius

CP = 13 cm and tangent PT = 12 cm

CT is the radius and TP is the tangent

CT is perpendicular TP

Now in right angled triangle CPT,

CP2 = CT2 + PT2 [using Pythagoras axiom]

(13)2 = (CT)2 + (12)2

169 = (CT)2 + 144

(CT)2 = 169 -144 =25 = (5)2

CT = 5 cm.

Hence the radius of the circle is 5cm

i

More Material