Central angles, Arcs, and Sectors

The measure of the central angle is equal to the measure of the arc intercepted by its rays.

• always true

• sometimes true

• never true

What is the area of a circle whose radius is 9cm?

• $9\pi\ cm^2$
  

• $18\pi\ cm^2$

• $40.5\pi\ cm^2$

• $81\pi\ cm^2$

What is the circumference of a circle whose diameter is 16ft?

• $8\pi\ ft$

• $16\pi\ ft$

• $32\pi\ ft$

• $64\pi\ ft$

Find the area of a circle, if its circumference is

 $15\pi\ cm$ .

•  $15\pi\ cm^2$  

•  $30\pi\ cm^2$  

•  $56.25\pi\ cm^2$  

•  $225\pi\ cm^2$  

What is the measure of angle ARV?

What is the measure of arc EV?

What is the length of arc JA if RV is 8cm?

• $\frac{20\pi}{9}cm$

• $\frac{22\pi}{9}cm$

• $\frac{10\pi}{3}cm$

• $4\pi\ cm$

Find the area of the sector ERI if JI is 18cm.

• $\frac{9\pi}{2}cm^2$

• $9\pi\ cm^2$

• $\frac{81\pi}{4}cm^2$

• $81\pi\ cm^2$

Solve for the area of the shaded region if ER = 5cm.

• $\frac{5\pi\ -10}{2}cm^2$

• $\frac{5\pi\ -\ 10}{4}cm^2$

• $\frac{25\pi\ -\ 50}{2}cm^2$

• $\frac{25\pi\ -\ 50}{4}cm^2$

What is the measure of angle JGO?