Learn about complementary and supplementary angles, as well as the definitions of adjacent and straight angles. Created by Sal Khan.

Review the basics of complementary and supplementary angles, and try some practice problems.

Review the basics of complementary and supplementary angles, and try some practice problems.

Use your knowledge about complementary and supplementary angles to find missing angles.

Finding trigonometric ratios of complementary angles (worked examples) Practice Quiz 1 Level up on the above skills and collect up to 160 Mastery points Start quiz

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In every right triangle, the two non-right angles are complementary. This is because the angles of a triangle add to 180º, so if the three angles are x, y, and 90º, then x+y+90º=180º Subtract 90º from …

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Learn about complementary and supplementary angles, as well as the definitions of adjacent and straight angles. Created by Sal Khan.

Sal shows that the sine of any angle is equal to the cosine of its complementary angle.