Answer:
1. The angle of depression is the angle formed by a horizontal line and the line of sight to an object below the horizontal line. In this case, the horizontal line is the surface of the ocean, and the line of sight is from Kristin to the coral reef. Since the angle of depression is 35° and the depth of the ocean at that point is 250 feet, we can use trigonometry to find the distance from Kristin to the reef.
We can imagine a right triangle formed by Kristin, the point on the ocean surface directly above the reef, and the reef. The depth of the ocean (250 feet) is the side opposite to the 35° angle, and the distance from Kristin to the reef is the side adjacent to that angle. We can use the tangent function to find that distance: tan (35°) = opposite/adjacent, so adjacent = opposite/tan(35°). Substituting in the known values gives us adjacent = 250/tan(35°), which is approximately 354.1 feet. So Kristin is about 354.1 feet away from the reef.
2. The Leaning Tower of Pisa currently leans at a 4° angle and has a vertical height of 55.86 meters. The vertical height of the tower is the side opposite to the 4° angle in the right triangle formed by the tower, the ground, and the imaginary vertical line from the top of the tower to the ground. The original height of the tower is the side adjacent to that angle.
We can use the tangent function to find the original height of the tower: tan(4°) = opposite/adjacent, so adjacent = opposite/tan(4°). Substituting in the known values gives us adjacent = 55.86/tan(4°), which is approximately 800.1 meters. So when it was originally built, the Leaning Tower of Pisa was about 800.1 meters tall.
3. From the information given, we can’t determine the width of the river. We need more information such as the distance William walked upstream or the angle between his new position and the tree on the other side of the river.
We can imagine a right triangle formed by the top of the building, the base of the building, and the base of the fountain. The height of the building (78ft) is the side opposite to the 72° angle, and the distance from the building to the fountain is the side adjacent to that angle. We can use the tangent function to find that distance: tan(72°) = opposite/adjacent, so adjacent = opposite/tan(72°). Substituting in the known values gives us adjacent = 78/tan(72°), which is approximately 24.6 feet. So, the fountain is about 24.6 feet away from the apartment building.
4. The angle of depression is the angle formed by a horizontal line and the line of sight to an object below the horizontal line. However, an angle of 720° is not a valid angle of depression because it is greater than 360°.
5. Diego has let out the entire 120ft of string and the angle the string makes with the ground is 52°. We can use trigonometry to find the height of his kite.
We can imagine a right triangle formed by Diego, the point on the ground directly below the kite, and the kite. The length of the string (120ft) is the hypotenuse of this triangle, and the height of the kite is the side opposite to the 52° angle. We can use the sine function to find that height: sin(52°) = opposite/hypotenuse, so opposite = hypotenuse*sin(52°). Substituting in the known values gives us opposite = 120*sin(52°), which is approximately 96.6 feet. So Diego’s kite is about 96.6 feet high at this time.