Question

Find the length of the tangent if d = 5 cm and r = 4 cm.

(a) 3 cm

(b) 4 cm

(c) 5 cm

(d) 9 cm

The question was asked in a national level competition.

This intriguing question comes from Tangent to a Circle in division Circles of Mathematics – Class 10

Answer 1

Right option is (a) 3 cm

For explanation I would say: The length of the tangent = \(\sqrt {d^2-r^2}\)

= \(\sqrt {5^2-4^2}\)

= √9

= 3