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Learn how to calculate the area and circumference of circles using formulas and examples. Includes step-by-step explanations with relevant calculations. Apply the formulas to find areas and perimeters.
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Formula for the area of a circle We can find the area of a circle using the formula Area of a circle = π×r×r or radius Area of a circle = πr2
The area of a circle Use π = 3.14 to find the area of this circle. 4 cm A = πr2 = 3.14 × 4 × 4 = 50.24 cm2
Find the area of this shape Use π = 3.14 to find area of this shape. The area of this shape is made up of the area of a circle of diameter 13 cm and the area of a rectangle of width 6 cm and length 13 cm. Area of circle = 3.14 × 6.52 13 cm 6 cm = 132.665 cm2 Area of rectangle = 6 × 13 = 78 cm2 Total area = 132.665 + 78 = 210.665 cm2
The area of a circle 2 cm 10 m 78 cm 23 mm Use π = 3.14 to find the area of the following circles: A = πr2 A = πr2 A = πr2 A = πr2
The circumference of a circle circumference π = diameter C π = d For any circle, or, We can rearrange this to make an formula to find the circumference of a circle given its diameter. C = πd
The circumference of a circle Use π = 3.14 to find the circumference of this circle. C = πd 8 cm = 3.14 × 8 = 25.12 cm
The circumference of a circle 9 m 4 cm 58 cm 23 mm Use π = 3.14 to find the circumference of the following circles: C = πd C = πd C = πd C = πd
Find the perimeter of this shape Use π = 3.14 to find perimeter of this shape. The perimeter of this shape is made up of the circumference of a circle of diameter 13 cm and two lines of length 6 cm. 13 cm 6 cm Perimeter = 3.14 × 13 + 6 + 6 = 52.82 cm