Complementary angle

This is the step-by-step, printable version. If you PRINT this page, any ads will not be printed.

See also the animated version.

After doing this Your work should look like this
Start with a angle BAC.
1.  Extend either leg (here AC) backwards, away from the interior of the angle.
2.  With the compass at any convenient width, make an arc each side of A, creating points P and Q.
3.  Make the compass width wider, and from P make an arc above A
4.  Repeat from Q, creating the point F above A.
5.  Draw a line from A, up through F
Done.  The angle ∠FAB and the given angle ∠BAC are complementary.
(I.E. they add to 90°)

Other constructions pages on this site




Right triangles

Triangle Centers

Circles, Arcs and Ellipses


Non-Euclidean constructions