# Lesson Plan: Right Triangle Trigonometry: Solving for an Angle Mathematics • First Year of Secondary School

This lesson plan includes the objectives, prerequisites, and exclusions of the lesson teaching students how to find a missing angle in a right triangle using the appropriate inverse trigonometric function given two side lengths.

#### Objectives

Students will be able to

- find an unknown angle measure in a right triangle (given a figure) using the sine, cosine, and tangent ratios, and their inverse functions,
- draw a figure from a question and determine an unknown angle in a right triangle,
- interpret and solve real-life and applied problems using right triangle trigonometry.

#### Prerequisites

Students should already be familiar with

- the Pythagorean theorem,
- solving for a side in a right triangle using the trigonometric ratios (sine, cosine, and tangent).

#### Exclusions

Students will not cover

- non-right triangle trigonometry.