Find measure of angle A if a=34, b=28 and c=15

A = 100.08 degrees

Step-by-step explanation:

If you are given all three sides, you could use the cosine law. For finding angle A, the equation would be

a² = b² + c² - 2bccosA

2bccosA = b² + c² - a²

cos A = (b² + c² - a²) / 2bc

A = arc cos ((b² + c² - a²) / 2bc)

A = arc cos ((28² + 15² - 34²) / 2*28*15)

A = arc cos (-0.175)

A = 100.08 degrees

I hope I was able to explain it clearly. Have a good day.