Circle Geometry and Formulas

The video tutorial covers the concept of circumference of a circle, focusing on solving problems using different formulas. It begins with an introduction to the topic, followed by detailed explanations of solving problems using the diameter and radius. The tutorial also discusses the use of variables and coefficients in formulas, and how to convert diameter to radius. The teacher provides step-by-step guidance to ensure understanding of the concepts.

What is the formula for the circumference of a circle when the diameter is known?

• C = πr²

• C = πd

• C = 2πr

• C = 2πd

If the diameter of a circle is 9 inches, what is the circumference using π as 3.14?

• 28.26 inches

• 30.00 inches

• 31.42 inches

• 25.12 inches

When should you use π as 22/7 instead of 3.14?

• When the diameter is a prime number

• When the circumference is a whole number

• When the radius is a multiple of 7

• When the diameter is a multiple of 5

What is the circumference of a circle with a radius of 7 using π as 22/7?

• 46 cm

• 40 cm

• 42 cm

• 44 cm

If a variable has no coefficient, what number is assumed to be in front of it?

• 0

• 2

• 1

• 10

What is the radius of a circle if the diameter is 1 yard?

• 2 yards

• 0.25 yards

• 1 yard

• 0.5 yards

How do you convert a diameter of 3.4 inches to a radius?

• Add 2

• Divide by 2

• Multiply by 2

• Subtract 2

What is the radius of a circle with a diameter of 3.4 inches?

• 2.7 inches

• 0.85 inches

• 3.4 inches

• 1.7 inches

Which formula can be used to find the circumference if the radius is known?

• C = d/2

• C = 2πr

• C = πr²

• C = πd

What is the circumference of a circle with a radius of 1.7 inches using the formula 2πr?

• 10.68 inches

• 12.68 inches

• 11.68 inches

• 9.68 inches