Question

Which of these pairs of quantities are proportional to each other?

a. Radius and diameter of a circle
b. Radius and circumference of a circle
c. Radius and area of a circle
d. Diameter and circumference of a circle

Answer 1

The pairs of quantities that are proportional to each other in a circle are the radius and diameter, radius and circumference, and radius and area.

Step-by-step explanation:

The quantities that are proportional to each other in a circle are:

• a. Radius and diameter: The diameter is always twice the length of the radius. So, if you double the radius, the diameter will also double.
• b. Radius and circumference: The circumference of a circle is equal to 2π times the radius. So, if you double the radius, the circumference will also double.
• c. Radius and area: The area of a circle is equal to π times the square of the radius. So, if you double the radius, the area will increase by a factor of four.

Therefore, the correct pairs of quantities that are proportional to each other are a, b, and c.