Name ______________________________
Unknown Angles
Module 2 Lesson 34
Learning Target: I can use a trigonometry to find unknown angles.
Opening Exercise
In right triangle ABC, hypotenuse length AB=15 and angle A=35°. Find leg length BC to the nearest
tenth.
Unknown Angles
1. You must build a wheelchair ramp so the slope is no more than 1 in. of rise for every 1 ft of run.
What is the maximum angle of elevation, to the nearest tenth of a degree?
2. Determine the measure of angle b to the nearest degree.
3. A 16 ft ladder leans against a wall. The foot of the ladder is 7 ft from the wall.
a. Find the vertical distance from the ground to the point where the top of the ladder touches
the wall.
b. Determine the measure of the angle formed by the ladder and the ground.
4. In right triangle ABC, hypotenuse length AB=15 and angle A=35°. Find leg length BC to the nearest
tenth.
Name ______________________________
Unknown Angles
Module 2 Lesson 34
Problem Set
2. A skateboard ramp has the dimensions shown. To the nearest degree, what angle does the ramp
make with the ground?
3. Determine 𝑚∠𝐴 and 𝑚∠𝐵 to the nearest tenth of a degree.
4. Use the given information to find the indicated angle to the nearest degree.
5. A man who is 5 feet 9 inches tall casts a shadow of 8 feet 6 inches. Assuming that the man is
standing perpendicular to the ground, what is the angle of elevation from the end of the shadow to
the top of the man’s head, to the nearest tenth of a degree?
6. A spring is attached to one end to support B and the other end to collar A, as represented in the
figure. Collar A slides along the vertical bar between points C and D. In the figure, the angle 𝜃 is the
angle created as the collar moves between points C and D. When the spring is stretched and the
distance from point A to point B is 5.2 feet, what is the value of 𝜃 to the nearest tenth of a degree?
Name ______________________________
Unknown Angles
Module 2 Lesson 34
Exit Ticket
1
1. Explain the meaning if the statement “arcsin 2 = 30°.” Draw a diagram to support your
explanation.
2. Gwen has built and raised a wall of her new house. To keep the wall standing upright while she
builds the next wall, she supports the wall with a brace, as shown in the diagram below. The bottom
of the brace is 3 ft. from the wall and the top of the brace is at a height of 5.5 ft. What is value of 𝑝,
the measure of the angle formed by the brace and the wall?