Trig problem solving.

1. Angles of Depression
More Trigonometry ...
Looking Down, Part I
... it's all about the angles and
how you look at them ...
Angles of Elevation
Beeches sunrise 3

2. Mental Math
(1) You just bought 40 L of gas. (6) Find 75% of 124 93
If you get a discount of 3.5¢/L, $1.40
how much money will you save?
(7) Find 75% of 110 82.5
(2) What is the cost of one
CD if 4 cost $82.00? $20.50
A B C D
1 Name Hourly Wage Hours Earnings
(3) What is the cost of one if 2 2 Abbie 7 4
$17.50
T-shirts cost $35.00? 3 Barry 8 5
4 Cindy 9 6
The following ingredients are used to make 5 David 10 7
18 banana muffins:
6 small, ripe bananas 1 cup brown sugar (8) Name one LABEL Name, Hourly
Wage, Hours,
1/2 cup white sugar 2 eggs in the spreadsheet. or Earnings
1/2 cup butter 3 cups flour (9) Write a spreadsheet formula
2 tsp. baking soda 2 tsp. baking powder that would calculate the average
1 cup chocolate chips 1 tsp. salt earnings of all 4 people.
(4) How much white sugar (5) How much butter is =AVERAGE(D2..D5)
is used to make 9 muffins? needed to make 45 muffins?
1/4 cup 1 1/4 cups
(10) What is 99 x 11? 1089

3. Determine each of the following ratios:
a) sin ∠B = b) cos ∠B =
c) tan ∠B = d) sin ∠A =
e) cos ∠A = f) tan ∠A =

4. Use your calculator to determine the value of the following trig ratios rounded
to four decimal places.
a) sin 45° = b) cos 60° =
c) tan 70° = d) sin 60° =
e) cos 45° = f) tan 45° =

5. In a right triangle, the leg adjacent to the angle of 25° is 12 cm long.
a) Draw a diagram of the triangle indicating the given angle and side.
b) What are the measures of the other angles?
c) How long is the side opposite the 25° angle to the nearest tenth of a
centimetre?
d) How long is the hypotenuse of the triangle?

6. A 4 m ladder leaning against a house makes a 65° angle with the ground.
How high up the wall of the house does the ladder reach?

7. A 15 m ramp is built to the loft door of the barn. The loft door is 5 m above
ground level. Find the angle that the ramp makes with the ground (angle of
elevation).

8. Skiers ski down a slope that is inclined at a 35° angle to the horizontal. If the
skiers reach ground level after travelling a distance of 1280 m, how high is the
slope where they began their run?