A circle is measured by a straight line across its widest part. This line is the __________ of the circle.

A. area

B. radius

C. volume

D. diameter

Aww -- Come on, Mary! This should be easy to answer.

If necessary, look up the definitions of each of your word choices. Write the meanings -- and memorize them!

Help me too...!! same question..!!

The correct answer is D. diameter.

To understand why the diameter is the correct answer, let's break it down:

A. Area: The area of a circle refers to the amount of space inside the circle. It is measured in square units, such as square meters or square inches.

B. Radius: The radius of a circle is the distance from the center of the circle to any point on its circumference. It is half the length of the diameter.

C. Volume: Volume is a measurement that applies to three-dimensional objects, such as solids. Circles are two-dimensional and do not have volume.

D. Diameter: The diameter of a circle is a straight line that passes through the center of the circle and divides it into two equal halves. It is the longest straight line that can be drawn within the circle, and it can be measured by extending a ruler from one edge of the circle to the opposite edge, passing through the center.

Therefore, the diameter is the correct answer when considering the straight line across the widest part of a circle.