Exercise 40 Page 445

Practice makes perfect

a The tangent ratio is the ratio of the opposite leg to the adjacent leg.

tan θ =Opposite/Adjacent

Note that the answer to this part has already been given. tan C = AB/BC However, we will still check the answer using the diagram.

b The sine ratio is the ratio of the opposite leg to the hypotenuse.

sin θ =Opposite/Hypotenuse To find sin C, we have to find the opposite leg to C and divide it by the hypotenuse.

c Similarly as in Part A, recall that the tangent ratio is the ratio of the opposite leg to the adjacent leg.

tan θ =Opposite/Adjacent To find tan A, we have to find the opposite and adjacent leg to A.

d The cosine ratio is the ratio of the adjacent leg to the hypotenuse.

cos θ =Adjacent/Hypotenuse To find cos C, we have to find the adjacent leg to C and divide it by the hypotenuse.

e The cosine ratio is the ratio of the adjacent leg to the hypotenuse.

cos θ =Adjacent/Hypotenuse To find cos A, we have to find the adjacent leg to A and divide it by the hypotenuse.

f The sine ratio is the ratio of the opposite leg to the hypotenuse.

sin θ =Opposite/Hypotenuse To find sin C, we have to find the opposite leg to C and divide it by the hypotenuse.

8.2.1 Angles of Polygons p.440-441

8.2.2 Areas of Regular Polygons p.445-448

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