Math Problem Statement

Two problems from the provided image: 1. Estimating the height of a tree using trigonometry based on angles of elevation and distance measurements. 2. Determining the distances of a ship from two observation points based on bearings and the Law of Sines.

Solution

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


Problem 10: Finding the Height of the Tree

We are given:

  1. Point AA, where the angle of elevation to the tree's top is 5151^\circ.
  2. Point BB, 25 ft away from AA, where the angle ABC=40\angle ABC = 40^\circ.

To find the height hh, we can use trigonometry and the Law of Sines.

Steps:

  1. Label the triangle:

    • ABC\triangle ABC, with AB=25ftAB = 25 \, \text{ft}.
    • A=51\angle A = 51^\circ and B=40\angle B = 40^\circ.
    • C=1805140=89\angle C = 180^\circ - 51^\circ - 40^\circ = 89^\circ.
  2. Apply the Law of Sines to find the hypotenuse ACAC: ACsin40=25sin89\frac{AC}{\sin 40^\circ} = \frac{25}{\sin 89^\circ} Since sin891\sin 89^\circ \approx 1: AC=25×sin4025×0.6428=16.07ft.AC = 25 \times \sin 40^\circ \approx 25 \times 0.6428 = 16.07 \, \text{ft}.

  3. Use trigonometry to find hh using A\angle A (angle of elevation): h=AC×sin51h = AC \times \sin 51^\circ h16.07×0.7771=12.49ft.h \approx 16.07 \times 0.7771 = 12.49 \, \text{ft}.

Answer for Problem 10: The height of the tree is approximately 12 feet.


Problem 11: Distance of the Ship from Two Points

We are given:

  1. Two observation points 18 miles apart along a shoreline.
  2. Bearings:
    • From the northern point: N32EN32^\circ E,
    • From the southern point: S58ES58^\circ E.

This forms a triangle with:

  1. The base AB=18miAB = 18 \, \text{mi} between the observation points.
  2. Interior angles:
    • A=18032=148\angle A = 180^\circ - 32^\circ = 148^\circ (angle at the northern point),
    • B=18058=122\angle B = 180^\circ - 58^\circ = 122^\circ,
    • C=180148122=10\angle C = 180^\circ - 148^\circ - 122^\circ = 10^\circ.

Steps:

  1. Apply the Law of Sines to find the distances ACAC and BCBC: ACsin122=BCsin148=18sin10.\frac{AC}{\sin 122^\circ} = \frac{BC}{\sin 148^\circ} = \frac{18}{\sin 10^\circ}.

  2. Solve for ACAC and BCBC:

    • AC=18×sin122sin10AC = \frac{18 \times \sin 122^\circ}{\sin 10^\circ},
    • BC=18×sin148sin10BC = \frac{18 \times \sin 148^\circ}{\sin 10^\circ}.
  3. Approximate values:

    • sin1220.848\sin 122^\circ \approx 0.848,
    • sin1480.629\sin 148^\circ \approx 0.629,
    • sin100.174\sin 10^\circ \approx 0.174.

    Compute:

    • AC18×0.8480.17487.69miAC \approx \frac{18 \times 0.848}{0.174} \approx 87.69 \, \text{mi},
    • BC18×0.6290.17465.05miBC \approx \frac{18 \times 0.629}{0.174} \approx 65.05 \, \text{mi}.

Answer for Problem 11:

  • Distance from northern point: 87.7 miles.
  • Distance from southern point: 65.1 miles.

Do you want detailed breakdowns of the calculations or further clarifications?

Follow-Up Questions:

  1. Would you like to see the Law of Sines derivation for both problems?
  2. Should I calculate using higher precision for Problem 11?
  3. Do you want a visual representation of the triangles in both problems?
  4. Would you like me to explain how bearings are used in trigonometric navigation problems?
  5. Should I round the answers differently?

Tip: Always label angles and sides clearly in geometry problems to avoid confusion when applying trigonometric formulas.

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Math Problem Analysis

Mathematical Concepts

Trigonometry
Law of Sines
Angles of Elevation
Bearings in Navigation

Formulas

Law of Sines: (a/sinA) = (b/sinB) = (c/sinC)
Height calculation using sine function: h = d × sin(θ)

Theorems

Law of Sines
Angle Sum of Triangle

Suitable Grade Level

Grades 10-12