Question

If an external point of a circle is at a distance equal to the diameter of the circle
from the centre of the circle, the length of the tangent drawn from the external
point is
a) 3r
b) 4r
c) 51
d) √3r​

Answer 1

Answer:

d)√3r

Step-by-step explanation:

Let r be radius

d be diameter which is equal to a line joing centre and external point

t be length of tangent..

t is perpendicular to r

Therefore by Pythagoras therom

d^2 = r^2 + t^2 (d=2r)

(2r)^2 = r^2 +t^2

4r^2=r^2+t^2

3r^2=t^2 (taking square root on both side)

√3r=t

OR THEREFORE

T=√2r