Formula to calculate the circumference and area of a circle These are the formulas to calculate the circumference and area of a circle: c = 2πr A = πr² = πd²/4 where: c stands for circumference; r for …

Aug 1, 2025 · Use this circle calculator to find the area, circumference, radius or diameter of a circle. Given any one variable A, C, r or d of a circle you can calculate the other three unknowns.

Know the formulas for the area and circumference of a circle and use them to solve problems; give an informal derivation of the relationship between the circumference and area of a circle.

Jul 23, 2025 · The formula for calculating a circle's circumference, or perimeter, is C = πd or C = 2πr, where "d" is the diameter and "r" is the radius. The formula A = πr2 represents the area of a circle, …

In this National 4 Lifeskills Maths study guide, you can revise how to find the perimeter and area of triangles, quadrilaterals (rectangle, parallelogram, rhombus, kite and square), circles,...

To calculate the area of a circle, use the formula A = πr², where 'r' is the radius. For the circumference, use C = 2πr or C = πd, where 'd' is the diameter.

Sep 24, 2024 · Finding the area of a circle is a straightforward calculation if you know the length of the circle’s radius. If you don’t know the radius, however, you can still calculate the area if you are given …

Dec 1, 2025 · Because π is the ratio between the circumference and the diameter, the circumference of a circle is equal to the diameter times π. Area of a circle is the region occupied by the circle in a two …

Circumference is a measure of the distance around the circle. Imagine cutting the circle and straightening it out; the length of the straightened line is the circumference. There are a few …

We are given that the radius (r) of the circle is 7 cm. Using the formula for the area of a circle, A = π r 2, we substitute the given value of the radius. This step is straightforward, involving only the substitution …