Question 1: Calculate the radius of a circle with a diameter of 14 cm.

Answer: 7

Question 2: A circle has a radius of 9 meters. Find its diameter.

Answer: 18

Question 3: If the radius of a circle increases from 5 cm to 8 cm, by how much does the area increase? (Use π ≈ 3.14)

Answer: Approximately 125.76 cm²

Question 4: Plot the graph of y=2x for x from 0 to 10. (Use the grid provided.)

Answer: Students will draw the line.

Question 5: Construct a circle with a radius of 4 cm. Label the radius clearly.

Answer: Students draw and label radius.

Question 6: A circular garden has a radius of 12 meters. What is its area? (Use π ≈ 3.14)

Answer: 452.16 m²

Question 7: A wheel has a radius of 0.5 meters. How far does it travel in 10 rotations? (Use 2πr for circumference)

Answer: Approximately 3.14 meters

Question 8: Identify and correct the mistake: 'The radius of a circle is equal to its diameter divided by 2.'

Answer: Correct statement; no mistake.

Question 9: Two circles have radii of 3 cm and 7 cm. What is the difference in their circumferences? (Use π ≈ 3.14)

Answer: Approximately 24.4 cm

Question 10: A large circular pond has a radius of 20 meters. A boat travels along the edge once. How far does the boat travel? (Use π ≈ 3.14)

Answer: Approximately 125.6 meters

Question 11: Challenge: Derive the formula for the area of a circle using the radius.

Answer: Students should explain that area = πr², based on the concept of approximation by sectors or calculus.