Question

the length of a tangent from a point a at a distance 5 cm from the centre of the circle is 4 cm find the radius of the circle ​

Answer 1

Answer:

Step-by-step explanation:

AB is a tangent drawn on this circle from point A.



∴ OB ⊥ AB 

OA = 5cm and AB = 4 cm (Given) 

In ΔABO, 

By Pythagoras theorem in ΔABO, 

OA2 = AB2 + BO2 

⇒ 52 = 42 + BO2 

⇒ BO2 = 25 - 16 

⇒ BO2 = 9 

⇒ BO = 3 

∴ The radius of the circle is 3 cm.

Answer 2

Step-by-step explanation:

5²- 4² = length of radius²

25-16 =radius²

√9 =radius

3= radius