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OBJECTIVE - G.SRT.D.11

Understand and apply the Law of Sines and the Law of Cosines to find unknown measurements in right and non-right triangles (e.g., surveying problems, resultant forces).

INTERPRETATION OF OBJECTIVE - G.SRT.D.11

Now that we know the law of sines and cosines... we can use them to solve for the missing information in triangles.

SKILLS

(1) The student will be able solve for the sides and angles of any triangle.

THE BIG IDEA

These two laws open the door to a great wealth of solving potential. It is these laws that form the basis of 'triangulation' and that we can calculate angles and distances when given three reference points.

TRAPS & PITFALLS

Not much to trap a student here... All of the issues have been laid out in the previous objective. Of course, if the data of AS1S2 is provided the student needs to remember the cases to determine what the possible outcomes are.

Bearings are not easy things for students to understand and they often require a number of examples. They are difficult because the bearing is often not the angle that is used in the problem; it is often the supplement to the bearing.

PAST CONNECTIONS

This objective simply applies what we learned in G.SRT.10.

FUTURE CONNECTIONS

Trigonometry is no longer right triangle only. We are now able to expand to many more real life situations to solve.

MY REFLECTIONS (over line l)

I love these types of problems. Students need to break down the descriptions into diagrams and then assess which law to use. I guess the only reflection I have, is the importance of diagramming. I spend a lot of time on the terminology used in descriptions and how that translated to our simplified diagram. If the diagram is wrong... then unfortunately, the answer will also be wrong.