Radius of a Circle Calculator

Introduction to radius of a circle calculator:

In mathematics, radius of a circle calculator is the calculator used to find the radius of the circle. In the radius of a circle calculator, we can find the radius value from any of the two values either by area or circumference. In the radius of a circle calculator, we can get the value of radius by just giving the value of circumference or area. The steps used in radius of a circle calculator are given below.

Radius of a Circle Calculator - Steps:

The diagram for the circle is given below:



Steps used in radius of a circle calculator are given below:

Step 1: Enter the value of circumference or area in the box given in the calculator.

Step 2: Then press "calculate" button.

Step 3: After some more second the process complete and shows the value of radius in the calculator.

Some of the examples based on this calculator is given below.

Radius of a Circle Calculator - Examples:

Example 1: Find the radius of the circle given that the area of circle is 153.86?

Solution:

Steps used in radius of a circle calculator  are given below:

Step 1: Enter the value of area as 153.86 in the box given in the calculator.

Step 2: Then press "calculate" button.

Step 3: After some more second the process complete and shows the value of radius as 7 in the calculator.I like to share this 6th grade math problems online with you all through my article.

Example 2: Find the radius of the circle given that the circumference of circle is 56.52?

Solution:

Steps used in radius of a circle calculator  are given below:

Step 1: Enter the value of circumference as 56.52 in the box given in the calculator.

Step 2: Then press "calculate" button.

Step 3: After some more second the process complete and shows the value of radius as 9 in the calculator.

Radius of a circle calculator – Practice problem:

Problem 1: Find the radius of the circle given that the area of circle is 379.94?

Answer is given below:

The output for that calculator is given below:



Problem 2:  Find the radius of the circle given that the circumference of circle is 81.64?

Answer is given below:

The output for that calculator is given below:

Geometry of circle

A circle is a conic section. When a cone is cut by a plane that is exactly perpendicular to the axis of the cone, the cross section we get is a circle. All points on the circle are equidistant from a fixed point in the circle. This fixed point is called the centre.

Radius of a circle:

The distance between the centre of a circle and any point on the circle is called the radius of that circle. The radius is half the diameter of the circle. So if we denote the radius by r and the diameter by d then, r = d/2

Circle formula:

We can measure the circumference of a circular object by winding a piece of fine string around the curved surface of the object exactly once and then measuring the length of the string with a meter scale. On measuring the circumference of a number of objects we find that the value of the ratio Circumference/diameter in each case is almost the same. This would always be some number between 3.1 and 3.2. This constant ratio is named by the Greek letter pi (pronounced as pi). Therefore we can write the formula for circumference of a circle as : C = pid, where d = diameter of the circle.

Area of a circle is given by the formula: A = pi*r^2 = pi * (d/2)^2 = (pi/4)d^2

Area of a semicircle:

We know that a semicircle is formed when a diameter divides a circle into two equal halves. So obviously the area of a semicircle is exactly half the area of the circle of the same diameter. Mathematically it is written like this,
A.S. = (pi/2)*r^2, where A.S. = area of semi circle, r = radius of the semi circle.

Area of a quadrant of a circle = (1/4)* pi*r^2

Circle Geometry:

Consider a unit circle centered at the origin(O) of a co-ordinate axis. A point Q on the circle is such that the line segment OQ makes an angle of h with the positive x axis. Then the co-ordinates of the point Q would be (cos(h), sin(h)). If the radius of the circle is r, then the co-ordinates of the point Q would be (r*cos(h), r*sin(h)).

From the above figure we see that triangle OQS is a right triangle. The radius of the circle is 1, so OQ = 1. Therefore adjacent side to angle h = cos(h) and opposite side to angle h = sin(h).