Question 1: What is the radius of a circle with a diameter of 14 cm?

Answer: 7

Question 2: Calculate the radius of a circle that has a circumference of 31.4 cm. (Use π ≈ 3.14)

Answer: 5

Question 3: A circular garden has a radius of 8 meters. What is the area of the garden? (Use π ≈ 3.14)

Answer: 201.06

Question 4: Plot the graph of y=2x on the grid provided. Identify the radius of a circle centered at origin passing through (4,8).

Answer: 4

Question 5: Construct a circle with a radius of 6 cm on the grid. Label the circle clearly.

Answer: Constructed circle with radius 6 cm

Question 6: If a circle's radius increases from 5 cm to 9 cm, by what factor does the area increase? Show your reasoning.

Answer: Approximately 3.24 times

Question 7: A circular pool has a diameter of 12 meters. What is its radius? Then, find the area of the pool.

Answer: Radius 6 meters, Area 113.04 m²

Question 8: Identify the common mistake: A student calculates the radius of a circle with circumference 31.4 cm as 15.7 cm. What's wrong and how should it be corrected?

Answer: Incorrectly using diameter instead of radius; radius should be circumference divided by 2π.

Question 9: A wheel has a radius of 0.5 meters. How far does it travel in one full revolution? (Use π ≈ 3.14)

Answer: 3.14 meters

Question 10: Challenge: Derive the formula for the radius of a circle in terms of its area, starting from the area formula A=πr².

Answer: r = √(A/π)

Question 11: An error occurred: Students often confuse diameter and radius. Rewrite the correct relationship between radius (r) and diameter (d).

Answer: d = 2r

Question 12: Given a circle with radius 10 cm, what is the length of a chord that is 8 cm from the center? (Use Pythagoras and assume the chord is bisected by a radius)

Answer: 6 cm