Circumference and Area of a Circle

The video tutorial introduces basic math concepts, focusing on the circumference of a circle. It explains the formulas for calculating circumference using either the diameter or the radius. The tutorial provides examples to demonstrate these calculations, including converting radius to diameter and using pi as 3.14 for practical calculations.

What is the term used to describe the distance all the way around a circle?

• Circumference

• Radius

• Diameter

• Area

Which formula can be used to calculate the circumference of a circle using the diameter?

• Circumference = 2d

• Circumference = 2πr

• Circumference = πd

• Circumference = πr²

How do you calculate the diameter if you only have the radius?

• Multiply the radius by π

• Divide the radius by 2

• Multiply the radius by 2

• Add π to the radius

If the radius of a circle is 5, what is the circumference in terms of π?

• 20π

• 15π

• 10π

• 5π

If the diameter of a circle is 100, what is the circumference when π is approximated as 3.14?

• 3.14

• 31.4

• 3140

• 314