M6 6.MG.1 Review- Circles

Which of the following best describes the relationship between the diameter and the radius of a circle?

• The diameter is half the radius.

• The radius is twice the diameter.

• The diameter is twice the radius.

• The radius is equal to the diameter.

Answer explanation

The diameter of a circle is defined as twice the length of the radius. Therefore, the correct relationship is that the diameter is twice the radius.

Tags

VA.6.MG.1.b

• 15.7 cm

• 31.4 cm

• 62.8 cm

• 78.5 cm

Answer explanation

To find the circumference, use the formula C = πd. With a diameter of 10 cm and π ≈ 3.14, C = 3.14 × 10 = 31.4 cm. Thus, the correct answer is 31.4 cm.

Tags

VA.6.MG.1.c

Answer explanation

The circumference of a circle can be expressed in terms of its diameter using the formula C = πd. This shows that the circumference is directly proportional to the diameter, making the correct choice C = πd.

Tags

VA.6.MG.1.d

• 153.86 cm²

• 154 cm²

• 150 cm²

• 140 cm²

Answer explanation

The area of a circle is calculated using the formula A = πr². Substituting r = 7 cm and π ≈ 3.14, we get A = 3.14 × (7)² = 3.14 × 49 = 153.86 cm². Thus, the correct answer is 153.86 cm².

Tags

VA.6.MG.1.e

• 2

• 3

• 3.14

• 6.28

Answer explanation

The ratio C/d represents the mathematical constant pi, which is approximately 3.14. Thus, measuring the circumference and diameter of circles will yield a value close to 3.14.

Tags

VA.6.MG.1.c

Answer explanation

The circumference of a circle is calculated using the formula C = 2πr, where r is the radius. This formula accounts for the full distance around the circle, making it the correct choice.

Tags

VA.6.MG.1.d

• 37.68 cm

• 38 cm

• 36 cm

• 40 cm

Answer explanation

To find the circumference, use the formula C = πd. Here, d = 12 cm. Thus, C = 3.14 × 12 = 37.68 cm. Therefore, the correct answer is 37.68 cm.

Tags

VA.6.MG.1.e

Name the circle part shown

• Diameter

• Radius

• Chord

• Tangent

Answer explanation

The radius is the distance from the center of the circle to any point on its circumference. It is half the length of the diameter, making it the correct answer for the circle part shown.

Name the circle part shown in red

• Diameter

• Radius

• Sector

• Tangent

Answer explanation

The red part shown is the diameter, which is the longest chord of the circle, passing through the center and connecting two points on the circumference. The radius is half the diameter, while a sector is a portion of the circle.

What is the area of this circle?

• 82.13

• 78.5

• 314.16

• 170.12

Answer explanation

The area of a circle is calculated using the formula A = πr². For a radius of 5, A = π(5)² = 25π, which is approximately 78.5. Thus, the correct answer is 78.5.