Solving Right Triangles with Trig Ratios

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Objective

I can solve the unknown side of right angles triangles using trigonometric ratios

Part 1 of 4

Warm-up video

YourMathGal · 10:16

We don't generate video — this one is by YourMathGal on YouTube. The practice questions and exit ticket below were drafted by AI for this objective, and every question is editable in the teacher guide.

Part 2 of 4

Key concepts

3 concepts

  1. 1

    Solving a right triangle means stating the measures of the three angles and the lengths of the three sides.

  2. 2

    If angle A is 40° and angle C is 90°, then angle B must be 50 degrees because angles A and B must add up to 90°.

  3. 3

    To solve for an unknown side, you can set up an equation using sine, cosine, or tangent, but you must know at least one side of the right triangle.

Part 3 of 4

Practice

5 questions

1

In a right triangle ABC, where angle C is 90 degrees and angle A is 60 degrees, what is the measure of angle B?

2

In right triangle XYZ, where angle Z is the right angle, side x (opposite angle X) is 5 units, and angle X is 35 degrees, which trigonometric ratio would you use to find the length of side z (the hypotenuse)?

Part 4 of 4

Exit ticket

Quick comprehension check

“In a right triangle, angle A is 35° and the side opposite to it (side a) is 15 units long. Find the length of the hypotenuse (side c). Round your answer to the nearest tenth.”

Sample answer included in the free materials

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