Solve the triangle. B = 36°, a = 41, c = 20
Solution:
Given B = 36°, a = 41, c = 20
According to the law of cosines, b2 = a2 + c2 - 2acCosB

b2 = 412 + 202 - 2(41)(20)cos(36°)
b2 = 1681 + 400 - 1640(0.8090)
b2 = 754.24
b = √(754.24)
b = 27.46
According to the laws of sines
sinA/a = sinB/b
sinA/ 41 = sin36°/ 27.46
sinA = 41× 0.021
sin A = 0.873
A = sin-1(0.873)
A = 60.84°
we know that the sum of all angles of a triangle is 180 degrees.
A + B + C = 180°
60.84 + 36 + C = 180°
C = 180 - 96.8
C = 83.15°
Solve the triangle. B = 36°, a = 41, c = 20
Summary:
By solving the triangle, B = 36°, a = 42, c = 18 we get b = 27.46, A = 60.84°and C = 83.15.
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