Applications of Trigonometry

Which ratio is used to find the adjacent side in a right triangle?

• Tangent

• Sine

• Cosine

• Secant

In a right triangle, what is true of angles A and B?

• They are supplementary

• They are both 90°

• They are congruent

• They are complementary

Which equation shows the Law of Cosines?

• a² = b² + c² + 2bc·cos(A)

• a² = b² + c² − 2bc·cos(A)

• a² = b² − c² + 2bc·cos(A)

• a² = b² + c² − 2ab·sin(A)

Which trig function equals opposite over hypotenuse?

• Cosine

• Tangent

• Sine

• Cotangent

If sin(35°) = x, what is cos(55°)?

• x

• 1 - x

• x²

• Not enough info

You know two angles and one side of a triangle. What law should you use?

• Law of Sines

• Law of Cosines

• Pythagorean Theorem

• SOH-CAH-TOA

You're given all three sides of a triangle. What do you use to find an angle?

• Law of Sines

• SOH-CAH-TOA

• Law of Cosines

• Complementary Angles

Which side is shared between sin(θ) and cos(90° – θ)?

• Adjacent

• Opposite

• Hypotenuse

• None

A triangle has sides 6, 8, and included angle 60°. What formula should you use?

• Law of Sines

• Law of Cosines

• SOH-CAH-TOA

• Pythagorean Theorem

Why wouldn't you use SOH-CAH-TOA in a triangle with no right angle?

• It's too slow

• It's not for acute angles

• You always use Law of Sines

• It only works in right triangles