Math 7 · Unit 2, Lesson 7: Circle Graphs · Tile 1 of 3

100 Percent and 360 Degrees

Two names for the same share

Finn reads this

A circle graph is a pizza cut by percent. Let's see who got the biggest slice.

The whole circle

Finn reads this

A circle graph shows how a whole splits into parts, so the whole circle is 100 percent. A circle is also 360 degrees, and you have measured angles since 4th grade. So every slice has two names: its percent of the whole, and its angle in degrees.

whole circle: 100% = 360°half: 50% = 180°a fourth: 25% = 90°a tenth: 10% = 36°1° = 1360 of the circle

ElleMath-speak

Each sector's angle equals its percent of 360 degrees.

FinnPlain English

The whole pizza is 100 percent and 360 degrees. Half the pizza is 50 percent and 180 degrees.

Percent to degrees

Finn reads this

A slice is 40 percent of the circle. Its angle is 40 percent of 360 degrees: 360 times 0.40 is 144 degrees. Going back, a 54 degree slice is 54 out of 360, which is 0.15, so 15 percent. Every slice is a proportional relationship with the whole.

40% of 360° = 360 × 0.40 = 144°54360 = 0.15 = 15%

Let me try a few

NC standards: NC.7.RP.3.

Where to go next

Let me try a few5 problems on 100 Percent and 360 Degrees. Next: Tile 2, Build a Circle GraphFavorite sports All tilesAll 3 parts of this lesson. Tell us what you thought about this tileA few quick questions about just this tile. It takes a few minutes, and opens in a new tab so you keep your place.