Trigonometry is one of the oldest and most useful tools in mathematics. Trigonometry is used in surveying forest, engineering, modelling periodic phenomena, and the list goes on. We can look at trigonometry in three distinct but highly interconnected ways in this unit. We can consider trigonometry as a relation of the sides of a right triangle, called right triangle trigonometry. Students will come to understand angle measurement in both degrees and radians and will be provided with experiences in applying the six trigonometric functions (including inverse functions) as functions of angles in standard position.