Question

LT 18.1

The radius of Circle A below is 11 millimeters and the measure of < BAC is 60°.

What is the length of Arc BC, to the nearest millimeter?

A. 12 mm
B. 24 mm
C. 6 mm
D. 3 mm

Answer 1

Answer: 12mm

Explanation:

Basically, you will find the circumference of the entire circle and then using that find the length of the arc.

So the circumference of the circle is its radius (11) times pi multiplied by 2.

2(11 x 3.14) = 69.08

Now a circle is always 360 degrees and the angle of the sector is 60 degrees.

So we have our circumference and we only need that small portion, so you take and make it a fraction and multiply by the circumference to find the length of that small portion:

60/360 x 69.08 = 11.51

Rounded = 12

Answer 2

`\textit{arc's length}\\\\ s = \cfrac{\theta \pi r}{180} ~~ \begin{cases} r=radius\\ \theta =\stackrel{degrees}{angle}\\[-0.5em] \hrulefill\\ r=11\\ \theta =60 \end{cases}\implies s=\cfrac{(60)\pi (11)}{180}\implies s=\cfrac{11\pi }{3}\implies s\approx 12~mm`