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7.2 Law of Cosines Day 1. Do Now Find the area of the triangle ABC given A = 113deg, b = 18.2 cm, c = 23.7 cm. p.608 #17-31 odds. Law of Cosines. In any triangle ABC, When the angle in between is a right angle, the law of cosines reduces to the Pythagorean Theorem. Ex1.
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7.2 Law of CosinesDay 1 Do Now Find the area of the triangle ABC given A = 113deg, b = 18.2 cm, c = 23.7 cm
Law of Cosines • In any triangle ABC, • When the angle in between is a right angle, the law of cosines reduces to the Pythagorean Theorem
Ex1 • Solve triangle ABC if a = 32, c = 48, B = 125.2 degrees
Ex2 • P.614 ex2
Ex3 • Solve triangle RST if r = 3.5, s = 4.7, t = 2.8
Ex4 • P.616 ex4
Closure • When would we choose the law of sines or law of cosines when solving a triangle? • HW: p.618 #1-15 odds 25 27 29
7.2 Law of CosinesDay 2 • Do Now • Solve the triangle ABC, if possible • B = 133 degrees, a = 12, c = 15
When to use Law of Sines/Cosines • Given the following sides/angles,
Closure • Determine which law applies, then solve the triangle ABC given a = 15, c = 7, B = 62 degrees • HW: p.619 #17-23 odds, 31-35 odds