Content Standards and Benchmarks:
II,3,1: Select and use appropriate tools; make accurate measurements using both metric
and common units, and measure angles in degrees and radians.
II,3,5:
Use proportional reasoning and indirect measurements including applications of trigonometric ratios, to measure inaccessible
distances and to determine derived measures such as density.
Objective:
After a class discussion
regarding the properties of triangles and working through a trigonometric (trig) proof, students will be able to justify their
algebraic steps for solving for trig values with definitions, theorems, and properties.
After showing students that using the Law of Sines is more efficient that doing a proof
for each trig problem, student will be able to apply the Law of Sines to solve trig problems.
Anticipatory Set:
Warm-up:
“When do we use the Pythagorean Theorem?”
Ø Given 2 sidesà find the
3rd
Ø Gives a length
Ø No angles involved
Class Discussion: I have a secret and a trick for your but we have
to work through some SCARY stuff first. We need to do a
proof! Proofs are scary because:
Ø
No set process
Ø
Higher order thinking
Ø
Can’t check work
Ø
Smart people do it
v
They really aren’t all that bad!
v
Let’s do one!
Input:
Ø How to do proofs: Justify your algebra with properties,
definitions, theorems, and Laws.
Ø How to apply the Law of Sines
