Question

A central angle θ in a circle of radius 4 m is subtended by an arc of length 5 m. find the measure of θ in degrees. (round your answer to one decimal place.)

Answer 1

Answer:

$\theta=71.6\°$

Step-by-step explanation:

step 1

Find the circumference of the circle

The circumference is equal to

$C=2\pi r$

we have

$r=4\ m$

substitute the values

$C=2\pi (4)=8 \pi\ m$

step 2

Remember that

360 degrees subtends the arc of length  $8 \pi\ m$ (circumference)

so

by proportion

Find the measure of θ by an arc of length 5 m

assume $\pi=3.1416$

$\frac{360}{8\pi}=\frac{\theta}{5}\\ \\ \theta=360*5/8\pi \\ \\ \theta=71.6\°$