How do you find the largest and smallest angle in a triangle with sides 3, 6 and 7?
1 Answer
Aug 16, 2015
Solve triangle knowing the sides: 3, 6, and 7
Ans: A = 12.53 deg; B = 96.38 deg
Explanation:
Apply the cosine law: a^2 = b^2 + c^2 - 2bc.cos A
Smallest angle A:
9 = 42 + 49 - 2(6)(7)cos A
Largest angle B:
49 = 9 + 36 - 2(3)(6)cos B
Angle C = 180 - A - B = 180 - 12.53 - 96.38 = 71.09 deg