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Cogito

Trigonometry · Chapter 1 · Lesson 1

Practice Worksheet

Solving Right Triangles

Choose the ratio that has what you know.

8 problems · about 19 minutes · G-SRT.C.8

NameDate

Figure — use these to answer the problems

Build a triangle and read off all three ratios and the angle.
adjacent = 4opposite = 3hyp = 536.87°
  • sin — opposite over hypotenuse0.60
  • cos — adjacent over hypotenuse0.80
  • tan — opposite over adjacent0.75
  • The marked angle36.87°
Adjacent leg4
Opposite leg3
Figure 1

Warm Up

Straightforward practice. Get the method working first.

4 problems

  1. Legs 20 and 21. Hypotenuse?

    Answer

  2. Which ratio involves the opposite and adjacent sides?

    • Tangent.
    • Sine.

  3. Legs 7 and 24. Hypotenuse?

    Answer

  4. Opposite 8, hypotenuse 10. Sine, as a decimal?

    Answer

Build It Up

The same ideas with more to keep track of.

2 problems

  1. Adjacent 6, hypotenuse 10. Cosine, as a decimal?

    Answer

  2. Which side is always the longest?

    • The hypotenuse.
    • The opposite side.

Stretch Yourself

Mixed problems. Work out what kind of question it is before you start.

2 problems

  1. The Ladder

    A right triangle has legs 9 and 12. What is the hypotenuse?

    Answer

  2. The Ratio

    Opposite 5, adjacent 12. What is the tangent, as a decimal to two places?

    Answer