The word trigonometry means triangle measurement You can

The word trigonometry means “triangle measurement. ” You can use trigonometry to calculate the lengths of sides and the measures of angles in triangles. Trigonometry has been used for centuries in the study of: surveying astronomy engineering © The Visual Classroom geography physics

B e s u n e t o p hy A © The Visual Classroom adjacent opposite C

B e s u n e t o p y adjacent h A © The Visual Classroom opposite C

B e t o opposite adjacent C p y h A © The Visual Classroom e s nu

B e s u n e t o p y h A © The Visual Classroom opposite adjacent C

B p y h A adj opp C SOH CAH TOA © The Visual Classroom

10 A © The Visual Classroom B hyp SOH CAH TOA 6 8 C adj opp

SOH CAH TOA B hyp 13 5 adj A © The Visual Classroom 12 opp C

Example 1: Determine side b B 55º SOH CAH TOA 8 cm A b = 8(tan 55°) b = 11. 4 cm © The Visual Classroom b C opp adj

Example 2: Determine side c if A is 31°. B hyp A c = 15. 2 cm 13 cm C adj SOH CAH TOA © The Visual Classroom

Ex. 3: From a distance of 20 m from the base a lighthouse the angle of elevation to the top of a lighthouse is 38º. Determine the height of the lighthouse. hh h = 20(tan 38°) h = 15. 6 38º 20 m The lighthouse is 15. 6 m high. © The Visual Classroom