Question

The radius of a circle is 5c.m and the distance between the centre of the circle to the point P is 7c.m. Find the length of the tangents.

Answer 1

radius = 5cm
Let the centre be O
so PO= 7cm
OS=5cm
PS will be the tangent
Tangents make right angle with the radius of circle ...
Let the point of intersection =S
So ΔPOS is a right angle Δ
PO²=PS²+OS²
PO²-OS²=PS²
7²-5²=PS²
49-25=PS²
24= PS²
√24=PS
2√6cm=PS

Answer 2

Length of tangent = √{( 7)^2 -(5)^2}

=√(49-25)

=√24

=2√6

=4.89cm