Mastering Circles: Area, Circumference, and More

What is the area of a circle with a radius of 5 cm?

• 78.5 cm²

• 50 cm²

• 31.4 cm²

• 100 cm²

Calculate the circumference of a circle with a diameter of 10 m.

• 40.84 m

• 15.70 m

• 25.12 m

• 31.42 m

Identify the center and radius of the circle given by the equation (x - 3)² + (y + 2)² = 16.

• Center: (2, -3), Radius: 5

• Center: (3, -1), Radius: 6

• Center: (3, -2), Radius: 4

• Center: (4, -2), Radius: 3

What is the formula for the area of a circle?

• A = 2πr

• A = πd

• A = r²/2

• A = πr²

If the circumference of a circle is 31.4 cm, what is its radius?

• 3 cm

• 10 cm

• 5 cm

• 7 cm

Graph the circle with the equation x² + y² = 25 on the coordinate plane.

• The circle is centered at (0, 0) with a radius of 5.

• The circle is centered at (5, 5) with a radius of 5.

• The circle is centered at (0, 0) with a radius of 10.

• The circle is centered at (3, 4) with a radius of 5.

What is the relationship between the diameter and radius of a circle?

• The radius is twice the diameter.

• The diameter is twice the radius.

• The diameter and radius are equal.

• The diameter is half the radius.

Solve for y in the circle equation (x - 1)² + (y + 3)² = 9.

• y = -3 ± √(9 - (x - 1)²)

• y = -3 ± √(x + 1)

• y = -3 ± 3 - (x - 1)

• y = -3 ± (x - 1)²

If a circle has an area of 78.5 cm², what is its radius?

• 5 cm

• 10 cm

• 7 cm

• 3 cm

What is the circumference of a circle with a radius of 4 inches?

• 16π inches

• 8π inches

• 12 inches

• 4 inches