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Cogito

Geometry · Chapter 1 · Lesson 3

Practice Worksheet

Angles in Polygons

Cutting a shape into triangles.

11 problems · about 22 minutes · G-CO.C.11

NameDate

Figure — use these to answer the problems

Count the sides and corners of the polygon.

Hexagon

Straight sides

6

Corners

6

Turn it0
Figure 1

Warm Up

Straightforward practice. Get the method working first.

4 problems

  1. Interior sum of a heptagon (7 sides), in degrees?

    Answer

  2. Interior sum of a quadrilateral, in degrees?

    Answer

  3. Interior sum of an octagon, in degrees?

    Answer

  4. One angle of a regular octagon, in degrees?

    Answer

Build It Up

The same ideas with more to keep track of.

3 problems

  1. Exterior angle sum of any polygon, in degrees?

    Answer

  2. One exterior angle of a regular hexagon, in degrees?

    Answer

  3. Interior sum is 1440°. How many sides?

    Answer

Stretch Yourself

Mixed problems. Work out what kind of question it is before you start.

4 problems

  1. How many triangles does a decagon cut into?

    Answer

  2. Select every statement that is true for all polygons.

    • Exterior angles sum to 360°.
    • Interior angles sum to 360°.
    • It cuts into n − 2 triangles.
    • Every angle is equal.
    • Tick every box that applies.

  3. The Pentagon

    Interior angle sum of a pentagon, in degrees?

    Answer

  4. Regular Pentagon

    One angle of a regular pentagon, in degrees?

    Answer