Download Maritime Industries Academy High PS#431 Lesson Plan Geometry

Maritime Industries Academy High PS#431
Lesson Plan
Geometry
Grade 11
Mr. Nathaniel M. Heralde
Unit 7: Right Triangles
Indicator: CLG 2.2.3. The students will solve problems using two-dimensional figures
and trigonometry
Topic: Angles of Elevation and Depression
Objective: The students will use the angles of elevation and depression and trigonometric
ratios in order to solve problems.
Materials: A Clinometer or a sextant if there is any.
Warm Up/Drill:
In this exercise the students will a) solve for the unknown side of a right
triangle given the angle of elevation or depression and one of the sides is
known and b) solve for the angle of elevation or depression when two sides
of the triangle are known.
Drill:
1. What is the length of the hypotenuse of a right triangle if the base
Measures 10 inches and the angle adjacent to the base is 30o.
2. The adjacent side and the opposite side of a right triangle measures 45 cm
and 87 cm respectively. Find the largest acute angle of the triangle.
Note: In this activity the students can work in pairs. The students will make their own
clinometer. If there is a sextant, the students will be taught how to use it.
Duration: 1 hour and 30 minutes
Lesson Proper:
1. Review of warm up/drill items
2. The students will go out of the hall way and will obtain data for the angle of elevation
and depression of designated objects in the hallway.
3. Review of the concept of angle of elevation and angle of depression.
4. Modeling examples on how to use solve right triangles.
5. The students will solve the following problems on their composition notebook and they
will write the steps on how to solve the problem and the difficulty encountered when
solving the problem. In each problem, the students will be required to draw a figure to
illustrate the problem.
Problem # 1
1. From a lighthouse that is 50 meters above sea level, the angle of depression of the
sailboat is 14o. To the nearest meter, how far is the sailboat from the base of the
lighthouse?
2. The angle of elevation from a speeding boat in a river to a bridge over the river is
40o. The boat is 58 meters from a point directly under the bridge. At that point, how
high is the bridge above the water?
3. A ship at A determines the angle of elevation of point C at the top of a cliff to be 14 o.
The ship then sails 600 meters closer to the shore and finds the angle of elevation
from point B to be 19o. Compute the height of point C above water level.
Independent Work:
Solve the following problem:
A radar operator on a ship at sea detects an airplane that is 6100 meters away and at
an altitude of 1100 meters. What is the angle of elevation from the ship to the plane?
Homework:
Solve the problem below:
A motorboat moving in the direction S 40o W passes a buoy that is due east of a
television tower. If the angle of elevation of the top of the tower from the buoy is
23o, what is the angle of elevation when the ship is closest to the tower?