Triangles
A triangle is a polygon with three sides. There are of course triangles
of different shapes and sizes. The applet below show triangles of many
shapes and sizes. Click the button to stop the action now and then and
take a look at the measures of the angles.
Record the measures in a table like the one below. What is the sum of the
measures?
| Angle A |
Angle B |
Angle C |
| 10° |
50° |
120° |
You should have noticed that the sum of the angles is always 180 degrees.
Watch the triangle carefully and try to stop the motion when it is
a right triangle. With practice you will get better at estimating the sizes
of angles.
Before you start the next applet get a piece paper and a pair of scissors
so that you can try to perform the demonstration in the applet for yourself.
