The formula for the area of a circle is A = πr2, where r is the radius of the circle. The unit of area is the square unit, for example, m2, cm2, in2 etc. In this article, we will learn terms related to circles, like radius, diameter, perimeter, area of the circle, etc. ...
cm, m, km etc. to measure a region we use a square as a unit. Hence, the unit of area is a unit square. This is written as unit2. Let us see who the different units are used to represent thearea of a surface.
Circumference of circle,C = \(\pi\)d Area of circle,A = \(\pi r^2\) Area of circle,A = \(\frac{\pi d^2}{4}\) Solved Examples Example 1:Find the diameter of a circle if its radius is 5 inches. Solution:As we know, that the diameter is twice the radius, so, ...
A radius is a line segment with one endpoint at the center of the circle and the other endpoint on the circle.Radius = Diameter2Diameter of a Circle:A line segment passing through the center of a circle, and having its endpoints on the circle, is called the diameter of the circle.Diamet...
Area = πr2= $\frac{22}{7}$ x 7 x 7 = 154 cm2 Suppose, instead of the radius we are given the diameter of a circle, how do we calculate the area? We know that in a circle, the radius is half of the diameter. Mathematically, ...
Example 2: Area of Circle A=πr2 Solve the equation for the radius, r. The equation has multiplication, and an exponent. When solving an equation, the order of operations is done in reverse, so undo multiplication, then the exponent. Aπ=πr2π (undo multiplication with division) To ...
Example 3: A tire from Karen’s car is shown below. What is the closest distance traveled, in feet, after 3 full rotations of the tire? Show Video Lesson Find radius or diameter of a circle when given the area From the formula A = πr2, we see that we can find the radius of a...
How to find the area of a circle using the radius The radius of a circle is the distance from the center of the circle to a point on the circle. Once you know this distance, you simply need to substitute the known value for r in the formula. ...
Question 3: Explain what is the formula of semi-circle perimeter? Answer: The circle’s circumference formula, C, is C = 2 * pi * r. A semicircle means half a circle. Therefore, in order to find the area of a semi-circle, one would need to divide the perimeter formula by two. Qu...
When one arc is smaller than the other one, the area enclosed by the smaller arc and the two radii is the area of the minor circular sector. How do you find the area of a shaded sector? Let a be the angle (measured in degrees) of a shaded sector of a circle of radius r. The ...