The pilot of a glider plane wants to estimate his altitude. He picks a landmark ahead and measures the angle of depression to be 20 degrees. He flies another 800 feet towards the landmark, remaining at the same altitude. The angle of depression from his new location to the same landmark is now 21.4 degrees. What is the glider's altitude?

Explanation:

The figure attached shows sketches the situation described.

You have two right triangles.

For the right triangle with the plane on the position A, you can write:

         ⇒ H = (800 + x) tan(20º)

For the right triangle with the plane on the position B, you can write:

        ⇒ H = x tan(21.4º)

To solve, equal both equations:

Substitute in the equation H = x tan(21.4º)

Rounding to one signficant figure that is 4,000 ft.

x=-2

infinite number of lines, so there is an infinite number of equations.

step-by-step explanation:

there are an infinite number of line that passes through the point (-2,5)

x=-2   is one line that passes through the point

y = 5 is another line that passes through the point

(these two lines are perpendicular to each other).

since the number of   numbers are infinite and the slope is the ratio of two numbers,(change in y over change in x) we can have an infinite number of slopes.     our only condition is that it passes through the point (-2,5)

answer: the distance

step-by-step explanation:

to calculate the distance d of a line segment with endpoints (x1, y1) and (x2, y2) use the formula d (x2 x1)2 (y2 y1)2. to calculate the midpoint of a line segment with endpoints (x1, y1) and (x2, y2) use the formula