Sin Cosine Complementary Angles

If cos α = sin β, what must be true about α and β?

• α and β are complementary angles

• α and β are congruent angles

• α and β are right angles

• α and β are supplementary angles

What are complementary angles?

• Angles that add up to 180°

• Angles that add up to 90°

• Angles that are equal to each other

• Angles that are opposite of each other when lines intersect.

What is the complement to: cos 40⁰ = ?

• sin 50⁰

• cos 50⁰

• tan 50⁰

• sin 40⁰

What is the complement to: sin 20⁰ = ?

• cos 70⁰

• sin 70⁰

• cos 20⁰

• tan 20⁰

What is true in respect to the relationship of the sine and cosine of complementary angles? A and B are the acute angles of the right triangle.

Select all that apply: What is true in respect to the relationship of the sine and cosine of complementary angles? A and B are the acute angles of the right triangle.

If sin x = cos y, what must be true about x and y?

• x + y = 90⁰

• x = y 

• x = 2y

What is true in respect to the relationship of the sine and cosine of complementary angles? A and B are the acute angles of the right triangle.

Select all that apply: What is true in respect to the relationship of the sine and cosine of complementary angles? A and B are the acute angles of the right triangle. 

• Cos (37)

• 12/15

• Sin (37)

• 15 * Sin(37)