Answer:
Explanation:
how to get the answer
a = 18
b = 30
c = 17
angle C = arcCos[ a^2 + b^2 - c^2 / 2*a*b ]
since we want angle A
angle A = arcCos[ b^2 + c^2 - a^2 / 2*b*c ]
A = arcCos [ 30^2 + 17^2 - 18^2 / 2*30*17 ]
A = arcCos [ 900 +289 -324 / 1020]
A = arcCos [865 / 1020]
A = arcCos[0.8480392]
A = 32.000° ( :o such accuracy )
A = 32.0 ° :) seem right?