8.1.5 Area of a circle and sector

8.1.5 Area of a Circle & Sector

By Ms. Madison

​Area of a circle

Multiple Choice

Calculate the area of the circle in terms of $$\pi$$

• 11π

• 22π

• 121π

• 200π

Multiple Choice

Calculate the area of the circle in terms of $$\pi$$

• 12.5π sq. cm

• 25π sq. cm

• 156.25π sq. cm

• 625π sq. cm

Multiple Choice

What is the area of the pizza if the radius is 6”?

• 
  $$6\pi$$

• $$12\pi$$

• $$36\pi$$

• $$144\pi$$

Multiple Choice

What is the area of an 18” pizza (the diameter is 18 inches)?

• $$9\pi$$

• $$18\pi$$

• $$81\pi$$

• $$324\pi$$

Multiple Choice

If the area of the pizza is 100π square inches, what is the radius?

• 5

• 10

• 50

• 100

Multiple Choice

If the area of the pizza is 169π square inches, what is the diameter?

• 13

• 26

• 84.5

• 169

Now let’s find the area of a slice of pizza 😋

Multiple Choice

You order a 12” pizza (the diameter is 12in). What is the area of the slice of pizza below?

• $$6\pi$$ sq. in.

• $$9\pi$$ sq. in.

• $$12\pi$$ sq. in.

• $$36\pi$$ sq. in.

Multiple Choice

You order a 12” pizza (the diameter is 12in). What is the area of the slice of pizza below?

• $$6\pi$$ sq. in.

• $$9\pi$$ sq. in.

• $$12\pi$$ sq. in.

• $$36\pi$$ sq. in.

Multiple Choice

You order a 18” pizza (the diameter is 18in). What is the area of the slice of pizza below?

• $$6\pi$$ sq. in.

• $$9\pi$$ sq. in.

• $$12\pi$$ sq. in.

• $$36\pi$$ sq. in.

What is a Sector of a Circle

The sector of a circle is the part enclosed by two radii and the included arc of a circle. It is represented by the symbol ⌔.

​

A slice is also known as a sector!

Multiple Choice

Calculate the area of the sector.

• $$9\pi$$ sq. m.

• $$18\pi$$ sq. in.

• $$36\pi$$ sq. in.

• $$324\pi$$ sq. in.

Open Ended

Describe how to calculate the area of a sector.