Lesson 4 Sine Law Learning Goal I can

Lesson 4: Sine Law Learning Goal: I can solve for a missing side or angle in a non-right triangle using sine law

Oblique Triangle • An oblique triangle is any non right triangle

Sine Law • Sine Law can be used to solve for unknown sides or angles in an oblique triangle when a matching sideangle pair is known Even though there are three terms in the equation, we only ever use two at once

Example 1 • Label each side of the triangle with the correct letter (a, b, c) • Write the sine law for the triangle shown and circle the ratios you would use • Use the information provided to solve for side b A 7. 2 B 37⁰ 95⁰ 48⁰ C

Example 2 Y Solve the triangle (find all unknown values) 21⁰ 17. 9 cm X 8. 7 cm Z

Lesson 4 Part Deux! Learning Goal: I can apply sine law to solve problems based on realistic situations

Example 1 A tent is being constructed for an outdoor wedding. If the tent is 11 m wide and the two identical support beams for the roof need to meet at an angle of 70 , how long do the support beams need to be?

Example 2 A plane flies between two tracking towers located 25 km apart. From station 1, the angle of elevation to the plane is 46 and from the second tower is 68. To one decimal place, what is the altitude of the plane?

Practice • Pg. 31 -32 #3 -6, 15 -17