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- AU Year 10 Maths
- Bearings
Bearings and direction word problems
- Intro Lesson5:56
- Lesson: 1a4:22
- Lesson: 1b2:21
- Lesson: 212:02
- Lesson: 34:27
- Lesson: 4a8:37
- Lesson: 4b0:41
- Lesson: 57:01
- Lesson: 69:05
Bearings and direction word problems
Lessons
Theorems that are useful:
Pythagorean Theorem: a2+b2=c2
Trig ratio: sinθ=HO
cosθ=HA
tanθ=AO
Law of sine: sinAa=sinBb=sinCc
Law of cosine: c2=a2+b2−2abcosC
- IntroductionIntroduction to Bearings and Direction Word Problems
- 1.Evaluate A Bearings Word Problem Using Trigonometric Ratios
Charlie leaves home for a bike ride, heading 040°T for 5km.
a)How far north or south is Charlie from its starting point?b)How far east or west is Charlie from its starting point? - 2.Solve A Bearings Word Problem Using the Law of Cosine
A camping group made a return journey from their base camp. From the camp, they first travelled 120°T for 3km. Then they travelled 210°T for 9km. Determine the direction and distance they need to travel if they want to return to the base camp now.
- 3.Analyze A Bearings Word Problem Using Trigonometric Ratios and the Law of Cosine
Melody and April go to the same school. Melody's home is 3.5km with a bearing of S16°W from school whilst April's home is 2.4km with a bearing of N42°E from school. How far away are their homes from each other?
- 4.Triangulate the Location of an Earthquake
Radar X detected an earthquake N55°E of it. 16km due east of Radar X, Radar Y detected the same earthquake N14°W of it.
a)Determine the earthquake from Radar X and Y.b)Which Radar is closer to the earthquake? - 5.Estimate the Height of an Object
A plane is sighted by Tom and Mary at bearings 028°T and 012°T respectively. If they are 2km away from each other, how high is the plane?
- 6.Applying Law of Sine and Law of Cosine
Consider the following diagram.
Find the distance between P and Q.