Circle Properties and Formulas

The video tutorial covers five key facts about circles. It starts by explaining that circles are 2D shapes, with spheres as their 3D counterparts. Circles are unique as they have only one side and no corners. The video then discusses important measurements in circles, such as the radius and diameter, and explains how to calculate the circumference using the formula pi times the diameter. Finally, it covers how to calculate the area of a circle using the formula pi times the square of the radius.

What is the 3D counterpart of a circle?

• Sphere

• Pyramid

• Cube

• Cylinder

How can you determine if a shape is 2D?

• It has volume

• It can roll

• It lays flat

• It has corners

What is a unique feature of a circle compared to other shapes?

• It has multiple sides

• It has corners

• It is 3D

• It has one side

How many corners does a circle have?

• One

• Four

• None

• Two

Which of the following is not a property of a circle?

• It is a 2D shape

• It is a 3D shape

• It has no corners

• It has one side

What is the longest straight line that can be drawn through a circle?

• Chord

• Radius

• Diameter

• Circumference

How is the radius of a circle related to its diameter?

• Radius is double the diameter

• Radius is half the diameter

• Radius is equal to the diameter

• Radius is unrelated to the diameter

If the diameter of a circle is 10 units, what is its radius?

• 5 units

• 10 units

• 15 units

• 20 units

If the radius of a circle is 4 units, what is its diameter?

• 16 units

• 2 units

• 4 units

• 8 units

What term describes the distance around the edge of a circle?

• Area

• Circumference

• Radius

• Diameter