A regular decagon has 10 equal sides.
There are no right angles in a regular decagon. On a regular decagon, the angles are 144 degrees, where as right angles are ninty.
No. It doesn't tessellate. (You cannot tile out an area with small decagons.) The sum of the measures of the interior angles of a polygon with n sides is (n-2)180° So the sum of all the interior angles in a decagon add up to (8x180)= 1440°. To find only ONE angle you need to divide 1440 by 10, yielding 144. 360 divided by 144 is 2.5, not an integral number. This shows that a decagon doesn't tessellate. In fact, only the regular (equilateral) triangle, the square, and the regular hexagon will tessellate. For example: The sum of all the interior angles in a triangle add up to 180. 180 divided by 3 is 60. 360 divided by 60 is 6 (an integral number). This shows that a triangle will tessellate. Try this method with a square (or hexagon) and you will see that it works (square 360/90=4 and hexagon 360/120=3).
No.
A decagon is a 10 sided polygon
Any polygon is regular if its sides are all the same length, or irregular if they're not. If all 10 sides of your decagon are the same length, then you have a regular decagon. If they're not, then you have an irregular one.
A regular decagon
The term decagon just means a 10 sided polygon. If the angles are all the same then it is regular. You have draw one that is regular and one that is not.
Each interior angle of a regular decagon is 144 degrees
Each interior angle of a regular decagon is 144 degrees
well the total degrees in a decagon is 1440 therefore each interior angle in a regular decagon would measure 144 degrese