Turn B has a sector area of [tex] \frac{5 \pi x}{20} [/tex]. What is the measure of the central angle for turn B?

Type the correct answer in the box. Use numerals instead of words. If necessary, use / for the fraction bar.

[tex]\[ m / B = \square \][/tex]



Answer :

To determine the measure of the central angle [tex]\(\theta\)[/tex] for turn B, we start by using the formula for the area of a sector of a circle. The formula for the area [tex]\(A\)[/tex] of a sector with central angle [tex]\(\theta\)[/tex] is:

[tex]\[ A = \left( \frac{\theta}{360} \right) \pi r^2 \][/tex]

Given the sector area is:

[tex]\[ A = \frac{5 \pi x}{20} \][/tex]

We will assume the radius [tex]\(r\)[/tex] of the circle is 1 for simplicity (since the problem does not specify the radius). Thus, the area of the sector simplifies and the formula for area becomes:

[tex]\[ A = \left( \frac{\theta}{360} \right) \pi (1)^2 = \left( \frac{\theta}{360} \right) \pi \][/tex]

We can equate the two expressions for the area of the sector:

[tex]\[ \left( \frac{\theta}{360} \right) \pi = \frac{5 \pi x}{20} \][/tex]

Next, we cancel [tex]\(\pi\)[/tex] from both sides of the equation:

[tex]\[ \frac{\theta}{360} = \frac{5 x}{20} \][/tex]

Simplify the right-hand side of the equation:

[tex]\[ \frac{\theta}{360} = \frac{x}{4} \][/tex]

To isolate [tex]\(\theta\)[/tex], multiply both sides of the equation by 360:

[tex]\[ \theta = 360 \times \frac{x}{4} \][/tex]

Simplify the multiplication:

[tex]\[ \theta = 90 x \][/tex]

Thus, the measure of the central angle [tex]\(\theta\)[/tex] for turn B depends on [tex]\(x\)[/tex]. If we assume [tex]\(x = 1\)[/tex], then:

[tex]\[ \theta = 90 \times 1 = 90 \][/tex]

Therefore, the measure of the central angle for turn B is:

[tex]\[ m / B = 90 \][/tex]