A circle has a diameter that is twice the radius; which statement is true?

A circle has a diameter that is twice the radius; which statement is true?

• A. Radius is twice the diameter
• B. Diameter equals radius
• C. Radius is half the diameter
• D. Diameter is quarter of the radius

Answer: (C)

Radius and diameter are directly tied: the diameter stretches across the circle and is twice as long as the radius. If the diameter is twice the radius, you can find the radius by dividing the diameter by two. That makes the radius half the diameter, which is the true statement. For example, if the radius is 4 units, the diameter is 8 units, so the radius is indeed half of the diameter. The other ideas don’t fit because they’d imply the radius is as big as or bigger than the diameter, or that the diameter is only a quarter of the radius, which contradicts the established relationship that the diameter is twice the radius.

Radius and diameter are directly tied: the diameter stretches across the circle and is twice as long as the radius. If the diameter is twice the radius, you can find the radius by dividing the diameter by two. That makes the radius half the diameter, which is the true statement. For example, if the radius is 4 units, the diameter is 8 units, so the radius is indeed half of the diameter. The other ideas don’t fit because they’d imply the radius is as big as or bigger than the diameter, or that the diameter is only a quarter of the radius, which contradicts the established relationship that the diameter is twice the radius.