## Right Triangles

About Math To Build On || Contents || On to 30° -60° Right Triangles || Back to Angles || Glossary

### Drawing Right Triangles

One of the most frequently drawn geometric shapes in the trades is the right triangle. Before you start working this practice, which involves drawing right triangles, think about what makes a triangle a right triangle.

One of the three angles of a right triangle must be a right angle (90° ).

Remember:

Two straight lines that cross each other at right angles are perpendicular lines.

First:

Near the center of a piece of paper,
draw a six inch straight line. Divide
the line in half and create a
perpendicular line through the center
point. Make the perpendicular above
the horizontal line 4" in length.

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Since you divided the horizontal line in half,
each horizontal line segment should measure
three inches in length.
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Second:

Draw a straight line from the end point of the horizontal line to the endpoint of the vertical line.

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Measure the last line you drew. It
should measure five inches.

If it does , the triangle created
is a 3-4-5 right triangle.

If it does not , then either the
length of one or both of the sides is
not exactly three and four inches or
the horizontal and vertical lines are not
perpendicular.

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On to Marking a 30° -60° Right Triangle