This page shows the different types of angles and their names: acute, right, obtuse, straight, and reflex.
For this investigation, create several different five-pointed stars. Then measure the internal angles of the five points. Record your measurements in a table. Use words, numbers, and pictures to clearly explain your findings.
Examples of stars:
Use this applet to investigate the sum of angles in polygons. Is there a pattern? Can you predict the sum of the angles in a 20-sided polygon?
Use the applet...
This is the cover page for the Lines and Angles pages.
What are vertical angles? This applet shows you.
A different demonstration of why the sum of the angles in a triangle is always 180°.
What is the sum of the angles in ANY triangle?
What are supplementary angles? Use this applet to find out.
Practice using a protractor with this applet.
If two angles are supplements, find the missing angle.