Question

The length of the tangent from a point A at a circle, of radius 3 cm, is 4 cm. The distance of A from the centre of the circle is
A. √7 cm
B. 7 cm
C. 5 cm
D. 25 cm

Answer 1

Answer:

The answer of this question is

C. 5cm

Using Pythagoras theorem

Answer 2

To calculate distance of the Point A from center of the circle we have to use the right angled triangle (Pythagorean Formula)

Explanation:

As per the figure, what we are given:-

Radius = 3cm.

AX = 4 cm. (length of tangent).

If A is the point and C is the center of the circle, then we have to calculate AC.

< AXC = 90˚. (Right angled at X as XC touches the tangent AX at X).

So, AC is the hypotenuse of the ∆ AXC.

  AX^2 + XC^2 = AC^2.

Or, AC^2 = AX^2 + XC^2.

 AC^2 = 4^2 + 3^2.

 AC^2 = 16 + 9

 AC^2 = 25

 AC = √ 25

AC = 5 cm.