## Reflection: Relevance Ambiguous Case Day 2 of 2 - Section 1: Bell Work

If the only goal was to determine the number of triangles, I would have students be more exact when the side opposite the given angle is smaller than the other side.  My goal is for students to solve problems with the Law of Sines.  I have students state there are 2 or 0 triangles when they have an acute angle and the opposite side is smaller.  When a student has reasoned that they may have 2 or no solutions, the student knows there will be 2 answers if when solving they get an answer for the angle.

Since real problems usually do not deal with special angles (30,45,60, etc.), students will be using calculators so the student will be able to determine when the situation does not have a solution.

I put a problem on the board that has no solution so they can see what the calculator states.  On the TI-84 it says domain error.  I do not go into more detail at this point.  We will discuss what is meant by domain error more when we develop the inverse trigonometric functions.

Why let students state 2 or no solutions
Relevance: Why let students state 2 or no solutions

# Ambiguous Case Day 2 of 2

Unit 6: Solving Problems Involving Triangles
Lesson 5 of 13

## Big Idea: By analyzing the information given a student can determine the number of possible solutions and find the solutions.

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Standards:
Subject(s):
Math, law of sines, triangles (Determining Measurements), Oblique Triangles, Ambiguous Case, problem solving, pre
45 minutes

### Katharine Sparks

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