Head First 2D Geometry

210 Chapter 5

slices are sectors

Need to work out how many MegaSlices is MegaSlice cutting each of

their pizzas into:

Total slices = 360º = 12

30º

Each slice is 30º

Sectors of a circle have angles totaling 360

o

This is a sector.

When a circle is divided up using lines that pass through the center

of the circle, the resulting “pizza slice” shapes are called sectors.

The MegaSlice sectors each have 30º angles, so a full pizza from

them would have to be 12 slices (30º × 12 = 360º). But they only

give you 10 slices, which means their deal gives you less than a

whole 12" pizza!

Each MegaSlice pizza is cut into 12 slices—so just 10 slices isn’t

even the whole pizza!

Use the information you have about the MegaSlice slices to work

out which is the better $10 pizza deal.

30º

360º in a whole turn

Mario gives you the whole 12" pizza, so Mario’s is a better deal.

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Sector angles always

add up to 360º

45º

45º 45º

45º

45º

45º45º

45º

30º

30º 30º

30º

30º

30º

30º

30º30º

30º

30º

30º