Question

The circumference of the circle in the above figure is 128 ft. What is the length of AB?

Answer 1

Answer: Option 'A' is correct.

Step-by-step explanation:

Since we have given that

Circumference of circle = 128 ft

So, as we know the formula for "Circumference of circle":

$C=2\pi r=128\ ft$

We need to find the length of an arc AB.

As we know that the formula for "Length of an arc":

$Length=\frac{\theta}{360\textdegree}\times 2\pi r\\\\L=\frac{45\textdegree}{360\textdegree}\times 128\\\\Length=16\ ft$

Hence, Option 'A' is correct.

Answer 2

To answer this question, you should set up a proportion: central angle/360 = arc length/circumference where the central angle = 45 and circumference = 128 ft. After you cross multiply, you should find that the arc length of AB equals 16 ft, which is A.