Answer: 72.6 cm
Step-by-step explanation:
Since we know the two sides and one angle, we would apply the law of Cosines which is expressed as
a² = b² + c² - 2abCosA
Where a,b and c are the length of each side of the triangle and C is the angle corresponding to AB.
AB² = 38² + 83² - 2(38 × 83)Cos61
AB² = 1444 + 6889 - 2(3154)0.4848
AB² = 8333 - 3058.1184
AB² = 5274.8816
Taking square root of both sides, it becomes
AB = √5274.8816
AB = 72.6 rounded up to the nearest tenth
