Game Development Reference
In-Depth Information
Note
Figure 12.9 features a mnemonic diagram that might prove useful as you memorize the trigo-
nometric ratios. The letter O designates the opposite side, the letter A designates the adjacent
side, and the letter H designates the hypotenuse. Start with STS to remember sine, tangent, and
secant. For the names of the other ratios, you prefix ''co.'' Then proceed from the notion that the
sine of theta is the ratio of O/H.
Figure 12.9
Recall STS, begin with sine and O/H.
Exercise Set 12.3
Show all six trigonometric ratios for right triangles with the designated values. Where the value of
the hypotenuse is not given, calculate it and proceed from there.
a. Opposite --- 3, Adjacent --- 4
b. Opposite --- 5, Adjacent --- 4, Hypotenuse --- 6
c. Opposite --- 5, Adjacent 4, Hypotenuse ---
p
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Ratios and Degrees
Generating values for the geometric ratios usually involves either knowing the
lengths of three sides of a right triangle or calculating this information using the
information available to you. As discussed previously, the most common starting
position for using the ratios involves employing the Pythagorean theorem to
