Constructing triangles

This can be done using a protractor or compass.

Using a protractor:

  • SAS (side – angle – side) – this is when you are provided with the side, angle and side of a given triangle and ask to draw it.

First you want to use a ruler to draw the length that you know. Then, you want to use a protractor the draw the angle that you are given. Lastly, use your ruler again to draw the last side that you are given and join the lines up.

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  • ASA (angle – side – angle) – you can also be provided with two angles and one side.

This is similar to SAS, except you have to use the protractor twice to draw both angles.

Using a compass:

  • SSS (side – side – side) – here you are given 3 sides. You will need a compass to construct this triangle.

You want to draw a straight line as the base, using the length you are given. Then place the compass on each point and open you compass to the appropriate lengths (using a ruler) and draw an arc. Do this again on the other side. You should have two arcs now.

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