Then,

(3) Therefore:

The above is known as the "law of sines," and should be interpreted: "Any

side divided by the sine of the angle opposite is equal to any other side

divided by the sine of the angle opposite it." This law, and the laws and

formulas in the following paragraphs, are useful in solving oblique

triangles.

EXAMPLE

Solve the triangle of figure 27, view B (on page 83) for angle C and side X

using the Law of sines.

SOLUTION

Angle C + 42,, + 75,, = 180,,, angle C + 117 = 180,,; therefore, angle C = 63,,.