Respuesta :

Answer:

A = (diameter/2)^2 x pi OR A = pi x (radius)^2

Step-by-step explanation:

To calculate the area of a circle, the following formula is used:

Area = pi x (radius)^2

In the problem, we are provided with the diameter of the circle, which is twice the length of the radius. Remember, the diameter is the length across the circle directly through the middle, whereas, the radius is the length from the edge of the circle to the middle.

TO solve for the area of the circle, we can follow this equation:

Area = pi x (diameter/2)^2

Area = pi x (42/2)^2

Area = pi x (21)^2

Area = pi x (441)

Area = pi441

Area = 1388.44236

The approximate area of the circle, with a diameter of 42 millimeters, and a radius of 21 millimeters, is 1385.44 millimeters squared.

Hope this helps! :)