Question

Select the correct answer from each drop-down menu. In a circle with a radius of 7 feet, the radian measure of the central angle subtended by an arc with a length of 4 feet is . The area of the sector formed by the arc is square feet. Assume π = 3.14, and round your answers to the nearest hundredth.

Answer 1

1. 0.57

2. 13.97

Explanation:

Answer 2

In a circle, the number of radians is proportional to the relative length of the arc, in comparison to the radius. We have that if we denote by x the radians, the following proportionality holds, relating angles and lengths:

`(x)/(2\pi) = (4)/(2 \pi 7)`
because the total of angles in radians is 2pi and the total circumference is 2pi times the radius. Hence, by solving for x we get: x=4/7=0.57 rad

We also have that the area is proportional to the angles. The total are is
`\pi r^2`. Hence, A=
`(4)/(2 \pi 7 ) *\pi* 7^2= 14 square feet.`