Math Problem Statement

Solve the right triangles in the image using trigonometric functions and the Pythagorean theorem.

Solution

Let's solve the problems shown in the image step by step.


Problem 14:

  • Triangle ABC\triangle ABC, where:
    • CAB=47\angle CAB = 47^\circ,
    • AB=3AB = 3 (hypotenuse),
    • Find AC=xAC = x (adjacent side).

Solution:

Using the cosine function: cos(θ)=adjacenthypotenuse\cos(\theta) = \frac{\text{adjacent}}{\text{hypotenuse}} cos(47)=x3\cos(47^\circ) = \frac{x}{3} x=3cos(47)x = 3 \cdot \cos(47^\circ) Using cos(47)0.682\cos(47^\circ) \approx 0.682: x30.682=2.046x \approx 3 \cdot 0.682 = 2.046 x2.05\boxed{x \approx 2.05}


Problem 17:

  • Triangle with sides:
    • Adjacent side = 4,
    • Opposite side = 8,
    • Find the hypotenuse xx.

Solution:

Using the Pythagorean theorem: x2=42+82x^2 = 4^2 + 8^2 x2=16+64=80x^2 = 16 + 64 = 80 x=80=165=458.944x = \sqrt{80} = \sqrt{16 \cdot 5} = 4\sqrt{5} \approx 8.944 x8.94\boxed{x \approx 8.94}


Problem 20:

  • Triangle ABC\triangle ABC, where:
    • AC=7.7AC = 7.7,
    • AB=14AB = 14,
    • Find θ\theta.

Solution:

Using the sine function: sin(θ)=oppositehypotenuse\sin(\theta) = \frac{\text{opposite}}{\text{hypotenuse}} sin(θ)=7.714\sin(\theta) = \frac{7.7}{14} sin(θ)0.55\sin(\theta) \approx 0.55 Using the inverse sine: θ=arcsin(0.55)\theta = \arcsin(0.55) θ33.4\theta \approx 33.4^\circ θ33.4\boxed{\theta \approx 33.4^\circ}


Let me know if you'd like more detailed explanations! 😊

Follow-up Questions:

  1. What other trigonometric functions can be used to solve Problem 14?
  2. How would you solve Problem 17 if given a missing side instead of the hypotenuse?
  3. What is the tangent value of θ\theta in Problem 20?
  4. How can the angle in Problem 20 be verified with another trigonometric ratio?
  5. What is the area of the triangle in Problem 17?

Tip: Remember to keep track of your calculator settings (degrees vs. radians) when solving trigonometric problems!

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Math Problem Analysis

Mathematical Concepts

Trigonometry
Right Triangles
Pythagorean Theorem

Formulas

cos(θ) = adjacent / hypotenuse
sin(θ) = opposite / hypotenuse
Pythagorean theorem: a^2 + b^2 = c^2

Theorems

Pythagorean Theorem
Trigonometric Ratios

Suitable Grade Level

Grades 9-11