Right angled trig
Which trig ratio uses opposite and hypotenuse?
sine (sin)
What is an angle of elevation?
The angle measured upward from the horizontal line of sight.
When do we use the sine rule?
When solving non-right-angled triangles with a matching side-angle pair.
How is a three-figure bearing written?
As three digits, measured clockwise from North, for example 045°.
What compass bearing is due East?
East
Find sin θ if opposite = 6 and hypotenuse = 10.
6/10 (0.6)
A person looks up at a tower. Is this elevation or depression?
Elevation
Write down sine rule
a/sinA =b/sinB = c/sinC
What is the three figure bearing of South?
180
Convert N 30° E into a three-figure bearing.
030
Find the missing side using tan 35° = x/12.
8.4
From the top of a cliff, a boat is seen below. What type of angle is formed?
depression
In triangle ABC, a = 10, A = 30°, B = 50°. Which side can be found using the sine rule?
b
What direction is a bearing of 090°?
East
What does S 40° W mean?
Start at South and turn 40° towards West.
A ladder is 5 m long and makes a 60° angle with the ground. Find the height reached.
4.3
A tree casts a 12 m shadow. The angle of elevation to the top is 35°. Find the height.
8.4
Find x if x/sin 40° = 12/sin 60°
8.9
A ship travels on a bearing of 135°. Which general compass direction is it moving?
S-E
Convert S 25° E to a three-figure bearing.
155
A right triangle has adjacent = 8 and hypotenuse = 17. Find the angle θ.
61.9 62)
A plane is flying at 800 m altitude. The angle of depression to a car is 12°. Find the horizontal distance.
3764
In triangle ABC, A = 42°, B = 68°, and a = 15 cm. Find side b.
20.8
The bearing from A to B is 070°. What is the bearing from B to A?
250
Convert a three-figure bearing of 300° into compass bearing form.
N 60 W