All Exams Test series for 1 year @ ₹349 only
Question

A surveyor has to measure the horizontal distance from her position to a distant reference point C. Using her position as the center, a 200 m horizontal line segment is drawn with the two endpoints A and B. Points A, B, and C are not collinear. Each of the angles $\angle CAB$ and $\angle CBA$ are measured as $87.8^\circ$. The distance (in m) of the reference point C from her position is nearest to

The correct answer is
2603

Geometric Setup

The problem involves a surveyor measuring the distance to a reference point C. The surveyor's position is denoted as 'O'. A horizontal line segment AB, 200 m long, is centered at 'O'. This means OA = OB = 100 m.

Angles <CAB> and <CBA> are measured as 87.8 degrees. These angles define a triangle ABC.

Since <CAB> = <CBA>, triangle ABC is an isosceles triangle, with sides AC = BC.

In an isosceles triangle, the line segment from the apex (C) to the midpoint of the base (O) is perpendicular to the base. Thus, CO is perpendicular to AB, making <AOC> = 90 degrees.

Trigonometric Calculation

The goal is to find the distance OC, which is the distance from the surveyor's position ('O') to point C.

Focus on the right-angled triangle AOC:

  • The length of the adjacent side AO is 100 m.
  • The angle <CAO> is 87.8 degrees.
  • The length of the opposite side OC needs to be calculated.

Using the tangent trigonometric relationship:

$ \tan(\angle CAO) = \frac{\text{Opposite}}{\text{Adjacent}} = \frac{OC}{AO} $

Substitute the known values into the equation:

$ \tan(87.8^\circ) = \frac{OC}{100 \text{ m}} $

Rearrange the formula to solve for OC:

$ OC = 100 \text{ m} \times \tan(87.8^\circ) $

Calculate the tangent value:

$ \tan(87.8^\circ) \approx 26.0306 $

Compute the distance OC:

$ OC \approx 100 \text{ m} \times 26.0306 $

$ OC \approx 2603.06 \text{ m} $

The distance to the reference point C is approximately 2603 m when rounded to the nearest meter.

Was this answer helpful?

Important Questions from Mathematics

  1. Geometric mean of 2, 6 and $x$ is equal to 6. What is the value of $x$ ?
  2. What is the equation of other diagonal ?  

  3. Which age group is the peak age of childbearing?
  4. What is the age specific fertility rate for the adolescent age group?
  5. Find out the total fertility rate?
Need Expert Advice?

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App