Marna is flying a helicopter at 1,350 feet and sees an airplane 2,400 horizontal feet in front of her, but is also an unknown vertical distance above her.

Marna knows the angle of elevation is 54 degrees. How far is the airplane from the ground? (1 point)
• 4,653 feet
• 5,245 feet
• 3,303 feet
• 4,714 feet

1 answer

To find the height of the airplane from the ground, we can use the tangent function, which relates the angle of elevation, the vertical distance, and the horizontal distance.

Let \( h \) be the vertical distance above Marna's helicopter to the airplane. Marna is at a height of 1,350 feet above the ground. The horizontal distance to the airplane is 2,400 feet, and the angle of elevation to the airplane is 54 degrees.

The formula for the tangent of the angle can be expressed as:

\[ \tan(\theta) = \frac{\text{opposite}}{\text{adjacent}} \]

In this case, the opposite side is the vertical distance \( h \), and the adjacent side is 2,400 feet. Thus, we can express this as:

\[ \tan(54^\circ) = \frac{h}{2400} \]

First, we can calculate \( \tan(54^\circ) \):

\[ \tan(54^\circ) \approx 1.3764 \]

Setting up the equation, we can solve for \( h \):

\[ 1.3764 = \frac{h}{2400} \]

Thus,

\[ h = 1.3764 \times 2400 \approx 3303.36 \text{ feet} \]

Now, to find the total height of the airplane above the ground, we add the height of Marna's helicopter:

\[ \text{Height of the airplane from the ground} = 1350 + 3303.36 \approx 4653.36 \text{ feet} \]

Therefore, rounding to the nearest whole number, the airplane is approximately 4,653 feet above the ground.

The correct answer is:

4,653 feet.