“Triangle Measurement” TRIGONOMETRY “Triangle Measurement”
The Triangle B c a C A b Angles : Capital Letters Sides: Lower Case Letters c a C A b
The Triangle Hypotenuse Opposite Adjacent A Opposite:Across From Adjacent:Part of A Adjacent Hypotenuse:Across From the Right Angle
SOHCAHTOA hypotenuse opposite A
SOHCAHTOA hypotenuse A adjacent
SOHCAHTOA Opposite A Adjacent
Labeling Triangles Adjacent Opposite Hypotenuse b a A c B Label the triangle according to angle A. Label the opposite side, adjacent side and the hypotenuse. Then name Angle B, side a, b, and c. Adjacent b Opposite a A c Hypotenuse B
Calculator Practice Determining trig values… Sin 52° = Cos 62° = Given the angle measure, use the sine (sin), cosine (cos) and tangent (tan) buttons, determine the trig values of each. Round to 4 decimal places. Sin 52° = Cos 62° = Tan 25° = .788010754 .7880 .469471563 .4695 .466307658 .4663
Calculator Practice Determining Angle Measures… Sin .9877 = Given the trig values, use the inverse function to determine the angle measures. Round to the nearest degree. Sin .9877 = Cos .9816 = Tan .8391 = 81.00427139 81º 11º 11.0081596 40º 40.0000124
Solving Triangles Solving triangles means to find all of the angles and all of the sides. Given the following triangle, find the missing side, set up the ratios, and find the missing angles. x = Sin A = Cos A = Tan A = Angle A = Angle B = 6 82 + x2 = 102 8/10 64 + x2 = 100 8 cm x2 = 100 - 64 6/10 10 cm x2 = 36 8/6 x = 6 53° A 90 - 53 = 37° x cm
Mnemonics "Tommy On A Ship Of His Caught A Herring" (probably more common in Great Britain than the United States). 2. "Oscar Has A Hold On Angie.” 3. "Oscar Had A Heap of Apples.” "The Old Army Colonel And His Son Often Hiccup" (which gives the functions in the order tangent, cosine, sine). 5. "Studying Our Homework Can Always Help To Obtain Achievement.”
Bonus Assignment: Create a Mnemonic to remember SOHCAHTOA