501 Geometry Questions

Vertices of a convex polygonall point outwards. All of the interior angles
of convex angles are less than 180°. Pentagon ABCDE below is convex
(“penta” means five, so a pentagon is a five-sided polygon).

If any of the vertices of a polygon point inward or if the measure of any ver-
tex exceeds 180°, the polygon is a concave polygon. In heptagon
ABCDEFG below, ∠D is greater than 180°, so it is a concave polygon.

F

G

D

E

A C

m D > 180, therefore polygon ABCDEFG is concave.

D

E

A

B

C

m A, B, C, D, E, < 180

D

F E

G

H

A B

C

1 2

3

4

6 5

7

8

sides: AB = BC = CD = DE = EF = FG = GH = HA

interior s: 1 ≅ 2 ≅ 3 ≅ 4 ≅ 5 ≅ 6 ≅ 7 ≅ 8

501 Geometry Questions