Question

Angle c is inscribed in circle O. AB is a diameter of circle O. what is the radius of circle.​

Answer 1

Answer: 7.5

Step-by-step explanation: Khan academy

Answer 2

The value of radius is 7.5 units

Explanation:

Given that a line that pass through the origin and form a triangle is a right-angle triangle. So in order to find the diameter/hypotenuse, you have to use Pythogaras Theorem :

`{c}^(2) = {a}^(2) + {b}^(2)`

Let a = 12 units,

Let b = 9 units,

Let c = hypo.,

`{hypo.}^(2) = {12}^(2) + {9}^(2)`

`{hypo.}^(2) = 225`

`hypo. = √(225)`

`hypo. = 15 \: \: units`

We have found out that the hypotenuse of the triangle is the diameter of circle. So in order to find radius, you have to divide it by 2 :

`radius = diameter / 2`

`radius = 15 / 2`

`radius = 7.5 \: \: units`