Circles And Circular Figures: Calculating the area of a circle

The video tutorial explains how to calculate the area of a circle using the formula pi times the radius squared. It highlights the importance of pi in geometry and provides examples to demonstrate the calculation process. The first example uses a circle with a given radius, while the second example involves converting a diameter to a radius before calculating the area. The tutorial emphasizes understanding the relationship between diameter, radius, and area in circular figures.

What is the formula for calculating the area of a circle?

• 2 * pi * r^2

• 2 * pi * r

• pi * d

• pi * r^2

If a circle has a radius of 2 cm, what is its area?

• 3.14 cm^2

• 12.56 cm^2

• 4 cm^2

• 6.28 cm^2

Why are the units of area always squared?

• Because it is a one-dimensional measurement

• Because area is a two-dimensional measurement

• Because it involves multiplying by pi

• Because it is calculated using the radius

How do you find the radius if you are given the diameter of a circle?

• Multiply the diameter by 2

• Divide the diameter by 2

• Square the diameter

• Subtract the diameter from pi

A circle has a diameter of 10 feet. What is its area?

• 50 feet^2

• 25 feet^2

• 31.4 feet^2

• 78.5 feet^2