Question

20. Find the radius of a circle if the length of tangent from a point at a distance of 25 cm
from the centre of the circle, is 24 cm.
Find
fihodratin polynomial y2 + 7 + 10 and verify the relationship
f the madratic nolynomial
1 dl​

Answer 1

Let P be the given point, O be the centre of the circle and PT be the length of tangent from P.

Then, OP=25 cm and OT=7 cm.

Since tangent to a circle is always perpendicular to the radius through the point of contact.

∴∠OTP=90o

In right triangle OTP, we have

OP2=OT2+PT2

⇒252=72+PT2

⇒PT2=252−72=(25−7)(25+7)=576

⇒PT=24 cm.

Hence, length of tangent from P=24 c