Math Problem Statement

Calculate all the unknown sides and angles of the triangle shown below, given the following measurements: B = 30°, c = 15.8 units.

Solution

We are solving a right triangle problem. The provided information includes:

  • Angle B=30B = 30^\circ,
  • Hypotenuse c=15.8unitsc = 15.8 \, \text{units}.

We need to calculate the following:

  1. The length of side bb (the base),
  2. The length of side aa (the height),
  3. The measure of angle AA.

Step 1: Recall basic trigonometric relations

In a right triangle:

  • sin(θ)=oppositehypotenuse\sin(\theta) = \frac{\text{opposite}}{\text{hypotenuse}},
  • cos(θ)=adjacenthypotenuse\cos(\theta) = \frac{\text{adjacent}}{\text{hypotenuse}},
  • tan(θ)=oppositeadjacent\tan(\theta) = \frac{\text{opposite}}{\text{adjacent}}.

Here:

  • sin(30)=0.5\sin(30^\circ) = 0.5,
  • cos(30)=320.866\cos(30^\circ) = \frac{\sqrt{3}}{2} \approx 0.866.

Step 2: Solve for aa (opposite side)

Using sin(B)=ac\sin(B) = \frac{a}{c}: sin(30)=a15.8.\sin(30^\circ) = \frac{a}{15.8}. Substitute sin(30)=0.5\sin(30^\circ) = 0.5: 0.5=a15.8.0.5 = \frac{a}{15.8}. Solve for aa: a=15.80.5=7.9units.a = 15.8 \cdot 0.5 = 7.9 \, \text{units}.

Step 3: Solve for bb (adjacent side)

Using cos(B)=bc\cos(B) = \frac{b}{c}: cos(30)=b15.8.\cos(30^\circ) = \frac{b}{15.8}. Substitute cos(30)=0.866\cos(30^\circ) = 0.866: 0.866=b15.8.0.866 = \frac{b}{15.8}. Solve for bb: b=15.80.86613.69units.b = 15.8 \cdot 0.866 \approx 13.69 \, \text{units}.

Step 4: Solve for angle AA

In a right triangle, the sum of the angles is 180180^\circ, and one angle is 9090^\circ. So: A=90B=9030=60.A = 90^\circ - B = 90^\circ - 30^\circ = 60^\circ.

Final Results

  1. b=13.69unitsb = 13.69 \, \text{units},
  2. a=7.9unitsa = 7.9 \, \text{units},
  3. A=60A = 60^\circ.

Would you like me to go into more detail about any of the steps?

Relative Questions:

  1. How can trigonometric functions be applied to other right triangle problems?
  2. What is the significance of the 30-60-90 triangle rule in solving this problem?
  3. Can you derive exact trigonometric ratios for 3030^\circ, 6060^\circ, and 4545^\circ?
  4. What are the practical applications of such triangle calculations?
  5. How can we verify the solution using the Pythagorean theorem?

Tip:

Memorize the special right triangle ratios for 3030^\circ-6060^\circ-9090^\circ triangles: 1:3:21:\sqrt{3}:2 (shorter leg, longer leg, hypotenuse). This helps solve these problems faster!

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Trigonometry
Right Triangle Properties
Angle Sum Property

Formulas

sin(θ) = opposite / hypotenuse
cos(θ) = adjacent / hypotenuse
Sum of angles in a triangle = 180°

Theorems

Basic Trigonometric Ratios
Angle Sum Property of a Triangle

Suitable Grade Level

Grades 9-12