Lesson 02: Exploring Circles | Unit 3: Measuring Circles

Draw

Use a geometric tool to draw a circle. Draw and measure a radius and a diameter of the circle.

Open Ended

Identify an example of a diameter in the circle. Explain your reasoning.

Open Ended

Identify an example of a radius in the circle. Explain your reasoning.

Open Ended

Lin measured the diameter of a circle in two different directions. Measuring vertically, she got 3.5 cm. Measuring horizontally, she got 3.6 cm. Explain some possible reasons why these measurements differ.

Multiple Choice

(A) is the center of the circle, and the length of (CD) is 15 centimeters. Which of the following is a radius, and how long is it?

• 5 cm
• 10 cm
• 7.5 cm
• 20 cm

Multiple Choice

(A) is the center of the circle, and the length of (CD) is 15 centimeters. Which segment is a diameter and how long is it?

• AB is the diameter and it is 10 centimeters long.
• CD is the diameter and it is 20 centimeters long.
• EF is the diameter and it is 15 centimeters long.
• CD is the diameter and it is 15 centimeters long.

Multiple Choice

What is the length of segment $$CD$$ ?

• 20 cm
• 5 cm
• 10 cm
• 15 cm

Multiple Choice

What is the length of segment $$AB$$ ?

• 3 cm
• 5 cm
• 7 cm
• 10 cm

Multiple Choice

Which segment has the same length as segment $$AB$$ ?

• Segment connecting A to point J
• Any segment connecting point A to points C, D, E, F, or G.
• Segment connecting A to point I
• Segment connecting A to point H