Arc Length and Sector Area

Arc Length, Circumference, and Sector Area

• ​Wanted to take a stretch of class today to review a few applications of Circles

• We will see these be the main focus of Part 1 of our Summative on Friday!

Multiple Choice

What is the circumference of this circle?  Round to the nearest tenth.

• $$\pi$$ cm 

• $$12\pi$$ cm

• $$6\pi$$ cm

• 68 $$\pi$$ cm

Multiple Choice

What is the green area called?

• Sector

• Circumference

• Arc Length

• Area

Multiple Choice

Find the approximate area of the shaded sector.

• $$9\pi\ cm^2$$

• $$5\pi\ cm^2$$

• $$7\pi\ cm^2$$

• $$3\pi\ cm^2$$

Multiple Choice

What is the area of the un-shaded sector?

• $$108\pi\ in^2$$

• $$36\pi\ in^2$$

• $$18\pi\ in^2$$

• $$6\pi\ in^2$$

Multiple Choice

What does 'L' represent?

• Sector

• Circumference

• Arc Length

• Area

ARC LENGTH

Multiple Choice

Calculate the LENGTH of arc ADC.

• 5040 $$\pi$$ cm

• 62 $$\pi$$ cm

• 44 $$\pi$$ cm

• 14 $$\pi$$ cm

Multiple Choice

Calculate the length of the bold arc.

• 49.7 ft

• 15.8 ft

• 24.9 ft

• 3.14 ft

Match

Match the following formulas.

• $$\ 2\pi\left(r\right)$$

• $$\ \pi\left(r\right)^2$$

• $$\ \frac{2\pi\left(r\right)\left(\theta\right)}{360\degree}$$

• $$\ \frac{\pi\left(r\right)^2\left(\theta\right)}{360\degree}$$

Circumference

Area

Arc Length

Area of Sector

• Circumference

• Area

• Arc Length

• Area of Sector

Now, let's try a couple challenge probs...

Multiple Choice

If the length of the 45° region of this circle is $$10\Pi$$   inches, what is the radius of the circle?

• 40 in.

• $$4\sqrt{5}$$  in.

• 10 in.

• 20 in.

Multiple Choice

In a​ circle, a 90° sector has area 64π in². What is the radius of the​ circle?

• 16 in

• 32 in

• 64 in

• 128 in