Solving right triangle (lesson plan)
Teacher: Dr. Frost
Subject Area: Mathematics
Grade Level: k11-12
Unit Title: Solving Right Triangles
Bench Mark: Solving Right Triangle
Indicator:
 Evaluate inverse trigonometric relations.
 Find missing angle measurement.
 Solve right triangle.
Materials/Resources Needed:
 Paper/pencils
 Graphing calculators
 Graphing paper
 Rulers
Anticipatory Set:
Ask students:
 Is it possible to disproving Angle Trisection
 Is it possible to trisect an arbitrary angle.
Objective/Purpose
Explain to students that one must use inverse trigonometric relationship when the value of the
trigonometric value is known, but not the angle itself.
Input:
Demonstrate to students how one can subdivide a segment into number of congruent segment.
Allow students to draw to rays and give them allow them to construct a figure with given angles.
Model:
Make a table on the board with two columns. On the top of the 1st column write Trigonometric Function
and on the other write inverse trigonometric relation.
Have students to come up with various formulas.
Check for understanding:
Ask students what to demonstrate the similarities and difference of the two functions.
Ask students to review the six trigonometric ratios.
Guided Practice:
Give three example s (hand-out) and allow them to solve the missing angles.
Closure:
Review the six trigonometric ration and their inverses.
Independent practice:
Hand-out p.194 (all)