Brigit is 15m away from the bottom of a tower.she spots a bird at an angle of elevation of 64°Also Rodger spots the same bird at an angle of elevation of 37°.Find the distance between Brigit and Rodger if they are on the same side of the tower to 2 decimal places.

1 answer

To solve the problem, we can use some trigonometry based on the angles of elevation and the distances involved.

Let:

  • \( h \) = height of the tower
  • \( b \) = distance from the base of the tower to Brigit = 15 m
  • \( d \) = distance from the base of the tower to Rodger
  • The angle of elevation from Brigit to the bird = \( 64^\circ \)
  • The angle of elevation from Rodger to the bird = \( 37^\circ \)

First, we can find the height \( h \) of the tower using Brigit's position:

Using the formula for the tangent of an angle: \[ \tan(\theta) = \frac{h}{\text{base}} \] For Brigit: \[ \tan(64^\circ) = \frac{h}{15} \] Thus, \[ h = 15 \cdot \tan(64^\circ) \]

Calculating \( h \): \[ h = 15 \cdot \tan(64^\circ) \approx 15 \cdot 1.9626 \approx 29.439 \text{ m} \]

Next, we find the distance \( d \) from the base of the tower to Rodger: Using the angle of elevation from Rodger: \[ \tan(37^\circ) = \frac{h}{d} \] Thus, \[ d = \frac{h}{\tan(37^\circ)} \]

Calculating \( \tan(37^\circ) \): \(\tan(37^\circ) \approx 0.7536\)

Now substituting in the value of \( h \): \[ d = \frac{29.439}{0.7536} \approx 39.06 \text{ m} \]

Now we can find the distance between Brigit and Rodger: \[ \text{Distance between Brigit and Rodger} = d - b = 39.06 - 15 = 24.06 \text{ m} \]

Therefore, the distance between Brigit and Rodger is approximately \( \boxed{24.06} \text{ m} \).