A quarter circle is one-fourth of a full circle. It is formed when a circle is divided into four equal parts/sections by two perpendicular lines that intersect at the circle's center. The shape resembles a segment of a pie or an arc with a right-angle sector.
The area of a quarter circle, also known as a quadrant, is a segment of a circle that represents one-fourth of its entire area and can be calculated using straightforward geometric principles. Understanding how to calculate the area of a quarter circle is essential in various fields such as geometry, engineering, and design.
1.0Area of a Quarter Circle Definition
A quarter circle is created when a circle is divided into four equal parts. Each of these parts is a 90-degree sector, or one-fourth of the circle. The area of a quarter circle can be determined if you know either the radius or the diameter of the original circle.
2.0What is 1/4 of a Circle Called?
One-fourth of a circle is called a quarter circle or a quadrant. This geometric shape is formed by dividing a full circle into four equal parts. Each part, representing a 90-degree sector, is a quadrant.
Key Characteristics of a Quarter Circle:
Angle: A quarter circle spans a 90-degree angle, which is one-fourth of the 360-degree angle of a full circle.
Area: The area of a quarter circle is one-fourth of the area of the entire circle.
Radius and Diameter: The quarter circle retains the same radius and half the diameter of the original circle.
3.0Area of a Quartile Circle Formulas
Calculating the area of a quarter circle, or a quadrant, involves using formulas derived from the area of a full circle. Here are the primary formulas based on whether you have the radius or the diameter of the circle.
Area of a Quarter Circle with Radius
The radius (r) is the distance from the center of the circle to any point on its circumference.
Area of a Full Circle:Afull =πr2
Area of a Quarter Circle:Aquarter =41πr2
Area of a Quarter Circle Using Diameter
The diameter (d) is the length of a line that passes through the center of the circle, connecting two points on its circumference. The radius is half of the diameter (r=2d) .
Convert Diameter to Radius:
r=2d
Substitute Radius into Full Circle Formula:
Afull =π(2d)2
Afull =π4d2
Area of a Quarter Circle:
Aquarter =41(π4d2)
Aquarter =161πd2
4.0Solved Examples on Area of a Quarter circle
Example 1: Find the area of a quarter circle with a radius of 6 units.
Solution:
Aquarter =41πr2
Aquarter =41π(6)2
Aquarter =41π(36)
Aquarter =9π
Therefore, the area of the quarter circle is 9π square units.
Example 2: Find the area of a quarter circle with a diameter of 8 units.
Solution:
Aquarter =161πd2
Aquarter =161π(8)2
Aquarter =161π(64)
Aquarter =4π
Therefore, the area of the quarter circle is 4π square units.
Example 3: A goat is tied to one corner of a rectangular field with dimensions 6 meters by 8 meters. The length of the rope θ is 5 meters. Calculate the area available for the goat to graze.
Solution:
The area grazed by the goat includes a quarter- circle sector with radius 5 meters and possibly parts outside the rectangular field.
Area of the quarter circle = 41πr2
A=41π(5)2
=425π≈ 19.63 square meters
Therefore, grazing area is 425 π square meters.
5.0Practice Questions on Area of a Quarter Circle
Find the area of a quarter circle with a radius of 5 units.
If the radius of a quarter circle is 3 units, what is its area?
Find the area of a quarter circle with a diameter of 10 units.
If the diameter of a quarter circle is 14 units what is its area?
A rectangle has dimensions such that a quarter circle can fit perfectly within it, with the quarter circle radius being 5 units. If the length of the rectangle is double its width, find the dimension of the rectangle and the area of the quarter circle.
Answers:
425π
49π
425π
449π
Length = 10, width = 5, Area =425π.
6.0Sample Questions on Area of a Quartile Circle
1. How do you calculate the area of a quarter circle?
Ans: To calculate the area of a quarter circle, use the formula: Area =41πr2 where r is the radius of the circle. This formula is derived from the area of a full circle πr2, divided by four.
2. What is the formula for the area of a quarter circle if the diameter is given?
Ans: If the diameter of the circle is given, first find the radius by dividing the diameter by 2. Then use the formula: Area =41π(2d)2
where d represents the diameter of the circle.
3. How can I find the area of a quarter circle if I only know the circumference?
Ans: If you know the circumference C of the circle, first find the radius using the formula:
r=2πC Then, use the area formula for the quarter circle: Area =41πr2
4. How does the area of a quarter circle compare to the area of a full circle?
Ans: The area of a quarter circle is one-fourth the area of a full circle. If the area of a full circle is πr2, then the area of a quarter circle is 41πr2.