In a triangle, find the value of a if �ÚA = 75�‹15', b = 4, and c = 9.
75° 15' = 75.25°
Use the cosine law
a^2 = b^2 + c^2 - 2(bc)cosA
= 16+81-2(36)cos75.25
= 78.668659...
a = √.... = 8.8695 or appr 8.87
Use the cosine law
a^2 = b^2 + c^2 - 2(bc)cosA
= 16+81-2(36)cos75.25
= 78.668659...
a = √.... = 8.8695 or appr 8.87