Practice for regular polygon angles and pictures of regular tilings

Here is a link to practice problems from 2011 dealing with the angles of regular polygons.

Here are pictures of some mix and match tilings of the planes, which will be on the Tuesday homework.

Here are more regular polygon problems.

The formula for total degrees of the angles on an n-gon is 180(n-2)° or [180n-360]°.

 The formula for the measure of a regular angle is [180-360/n]°.

a) What is the sum of all the angles of a 20-gon?

b) What is the regular angle measure of a 20-gon?

c) What is the sum of all the angles of a 30-gon?

d) What is the regular angle measure of a 30-gon?


Answers to these questions in the comments.

regular tilings, platonic solids and Penrose tiles

Here are links to several posts with pictures from another blog I write that isn't all about math.

Regular tilings of the plane. (The stuff we talked about this Tuesday and we will continue to discuss it on Thursday before the Spring break.)

Platonic solids. (Kind of the same idea, but in three dimensions.)

Truncated platonic solids. (Things like soccer balls and geodesic domes.)

Penrose tiles. (Sir Roger Penrose made two non-regular quadrilaterals that can tile the plane, but not following the same pattern at every corner.)