Angles of a polygon: add up the triangles

Answer Key - Grade 8 Math Worksheet - Challenge Me

Circle the best answer, or write your answer on the line.

1. 1.

   The angles of Jun's hexagon paper cut-out are (x + 20)°, (x + 20)°, (2x)°, (2x)°, (x + 40)° and (x + 40)°. How many degrees is the largest angle?

   150
2. 2.

   The angles of Kira's octagon shape drawn on paper are x°, x°, x°, x°, (x + 30)°, (x + 30)°, (x + 30)° and (x + 30)°. How many degrees is the largest angle?

   150
3. 3.

   The angles of Luz's pentagon shape cut from paper are (x + 50)°, (x + 50)°, (x + 10)°, (x + 10)° and x°. How many degrees is the largest angle?

   134
4. 4.

   The inside angles of Milo's paper polygon add up to 1440°. How many sides does it have?

   10
5. 5.

   a polygon with its sides not counted; the angle total 1980° written inside. The inside angles of Noah's paper cut-out with many sides add up to 1980°. How many sides does it have?

   13
6. 6.

   The inside angles of Pia's polygon drawn in pencil add up to 2340°. How many sides does it have?

   15
7. 7.

   The inside angles of Ren's big polygon drawn in crayon add up to 3240°. How many sides does it have?

   20
8. 8.

   Each inside angle of Tala's regular shape drawn on paper is 140°. How many sides does it have?

   9
9. 9.

   Each inside angle of Zee's regular paper cut-out is 150°. How many sides does it have?

   12
10. 10.

    a regular polygon, each inside angle 156°; one side extended to show the outside angle. Each inside angle of Bo's regular shape cut from paper is 156°. How many sides does it have?

    15