The airspeed indicator of an airplane is circular, with a diameter of 2.75 in. Use the rules for working with measurements. What is the circumference and area of the indicator? A) The length is 8.64 in., the area is 11.9 in ². B) The length is 8.64 in., the area is 23.8 in ². C) The length is 17.3 in., the area is 11.9 in ². D) The length is 8.64 in., the area is 5.94 in ². E) The length is 17.3 in., the area is 5.94 in ².

Question

Quizplus · Accepted Answer

The circumference (length) of a circle is given by $C = \pi d$, where $d$ is the diameter. For a diameter of 2.75 in, $C = \pi \times 2.75 \approx 8.64$ in. The area of a circle is given by $A = \pi r^2$, where $r$ is the radius. The radius is half the diameter, so $r = 2.75 / 2 = 1.375$ in. Thus, $A = \pi \times 1.375^2 \approx 5.94$ in$^2$.

The Airspeed Indicator of an Airplane Is Circular, with a Diameter