Question

For the circle, a 70° central angle cuts off an arc of 8 inches what is the circumference of the circle (there are 360° in a circle)

Answer 1

Answer: 41.14 inches

Step-by-step explanation:

The formula to find the length of an arc :-

$l=C\times\dfrac{\theta}{360}$, where C is the circumference of the circle, $\theta$ is the central angle cuts off an arc of length 'l'.

Given : Central angle : = $\theta = 70{\circ}$

Length of arc: $l= 8\ inches$

Now, substitute all theses value in the above formula , we get

$8=C\times\dfrac{70}{360}\\\\\Rightarrow\ 8=C\times\dfrac{7}{36}\\\\\Rightarrow\ C=\dfrac{36\times8}{7}=41.1428571429\approx41.14\text{ inches}$

Hence, the circumference of the circle is about 41.14 inches.

Answer 2

There are 360° in a circle, now, this "sector" of the circle has an angle of 70°, so for 70°, there are 8in or circumference, or arc length

how much arc length or circumference in 360° then?

well $\bf \begin{array}{ccllll} degrees&circumference\\ -----&--------\\ 70&8\\ 360&x \end{array}\implies \cfrac{70}{360}=\cfrac{8}{x}$

solve for "x"