in High School Math

Basic Trigonometry Word Problems

1.9k Views

Basic Trigonometry Word Problems

Trigonometry is a branch of mathematics that studies relationships between the sides and angles of triangles. It is a powerful tool that can be used to solve a wide variety of problems in many different fields, including engineering, physics, and architecture. In this blog post, we will explore some basic trigonometry word problems and how to solve them.

Understanding the Basics

Before we dive into word problems, let's review some basic trigonometry concepts:

  • Sine (sin): The ratio of the opposite side to the hypotenuse in a right triangle.
  • Cosine (cos): The ratio of the adjacent side to the hypotenuse in a right triangle.
  • Tangent (tan): The ratio of the opposite side to the adjacent side in a right triangle.

These ratios can be represented using the acronym SOH CAH TOA:

  • SOH: Sine = Opposite / Hypotenuse
  • CAH: Cosine = Adjacent / Hypotenuse
  • TOA: Tangent = Opposite / Adjacent

Solving Word Problems

Here is an example of a basic trigonometry word problem:

Problem: A ladder is leaning against a wall. The ladder is 10 feet long and makes an angle of 60 degrees with the ground. How high up the wall does the ladder reach?

Solution:

  1. Draw a diagram: Draw a right triangle representing the ladder, the wall, and the ground. The ladder is the hypotenuse, the wall is the opposite side, and the ground is the adjacent side.
  2. Identify the known values: We know the length of the hypotenuse (10 feet) and the angle (60 degrees). We want to find the length of the opposite side.
  3. Choose the appropriate trigonometric function: Since we know the hypotenuse and want to find the opposite side, we will use the sine function (SOH).
  4. Set up the equation: sin(60°) = opposite / 10
  5. Solve for the opposite side:
    • sin(60°) = 0.866
    • 0.866 = opposite / 10
    • opposite = 0.866 * 10 = 8.66 feet

    Answer: The ladder reaches 8.66 feet up the wall.

    Additional Tips

    • Always draw a diagram: Visualizing the problem helps you understand the relationships between the sides and angles.
    • Identify the known values and what you need to find: This will help you choose the correct trigonometric function.
    • Use a calculator to find the trigonometric values: Most calculators have buttons for sine, cosine, and tangent.

    Practice Problems

    Here are some additional practice problems to help you master solving trigonometry word problems:

    1. A 20-foot tall tree casts a 15-foot shadow. What is the angle of elevation of the sun?
    2. A boat is 100 meters from the base of a cliff. The angle of elevation from the boat to the top of the cliff is 35 degrees. How tall is the cliff?
    3. A ramp is 12 feet long and has a slope of 10 degrees. How high is the ramp at its highest point?

    Remember to practice and use the tips above to help you solve these word problems.

    For more in-depth learning and practice, you can check out the following resources:

    Good luck with your trigonometry studies!

Trigonometry