Perimeter and Area of a Circle - A Review A circle is a closed curve with a constant circumference, which is the distance around the circle. It has a constan...
A circle is a closed curve with a constant circumference, which is the distance around the circle. It has a constant area, which is the amount of space inside the circle, regardless of the size of the circle.
Perimeter:
The perimeter is the total length of the circle's circumference.
It is equal to the circumference of a circle, which is 2πr, where r is the radius of the circle.
The perimeter of a circle with radius r is always 2πr.
Area:
The area is the amount of space inside the circle.
It is equal to πr^2, where r is the radius of the circle.
The area of a circle with radius r is always πr^2.
Examples:
The circumference of a circle with radius 5 cm is 2π(5 cm) = 31.4 cm.
The area of a circle with radius 3 cm is π(3 cm)^2 = 9π cm^2.
Additional Notes:
The perimeter and area of a circle are both measures of the size of the circle.
Both the perimeter and area are always positive.
The perimeter and area of a circle are related by the formula:
P = 2πr
A = πr^2
By understanding the concepts of perimeter and area, students can apply them to solve various real-world problems related to circles