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  1. Krista is trying to solve for x in the triangle at right. Homework Help ✎

    1. What equation could Krista write?

    2. Krista does not have a scientific calculator with trig buttons on it, but she does remember something funny her friend Juanisha told her. Juanisha’s favorite sine ratio is sin 31.5º ≈ 0.522 because 5/22 is Juanisha’s birthday! Without using the trig buttons on your calculator, use Juanisha’s favorite ratio to solve your equation from part (a).

With the given angle of 58.5°, x is the adjacent side and 7 is the hypotenuse.
Which trigonometry ratio should you use?

Remember the sine of one acute angle in a right triangle equals the cosine of the other acute angle.
Find the measure of the missing angle in the triangle, then use sine ratio.