Exploring Radius, Diameter, and Circumference

This video tutorial provides a refresher on the basic concepts of radius, diameter, and circumference of a circle. It explains the relationships between these elements and demonstrates how to calculate each using simple formulas. The video includes examples and practice problems to reinforce understanding, focusing on the use of pi in calculating circumference and the conversion between radius and diameter.

What is the diameter of a circle if its radius is 5 units?

• 5 units

• 15 units

• 10 units

• 20 units

If the diameter of a circle is 22 units, what is its radius?

• 44 units

• 22 units

• 33 units

• 11 units

How do you calculate the circumference of a circle?

• Radius times π

• Diameter times π

• Diameter plus π

• Radius squared times π

What is the approximate value of π?

• 22/7

• 3.14

• 3.14159

• All of the above

If the diameter of a circle is 14 units, what is its circumference using π as 3.14?

• 28 units

• 42 units

• 44 units

• 43.96 units

Given a circle with a radius of 10 units, what is its circumference?

• 40 units

• 10π units

• 62.8 units

• 20π units

If the circumference of a circle is 33π units, what is its diameter?

• 99 units

• 66 units

• 16.5 units

• 33 units

A circle has a circumference of 48π units. What is its radius?

• 12 units

• 24 units

• 96 units

• 48 units

Find the diameter of a circle if its circumference is 31.4 units.

• 20 units

• 5 units

• 10 units

• 15.7 units

If the circumference of a circle is 42π units, what is its radius?

• 42 units

• 84 units

• 21 units

• 10.5 units