Answer:
28.9
Step-by-step explanation:
a^2 = b^2 + c^2 − 2bc*cos(A)
a^2 = 23^2 + 21^2 − 2*23*21*cos(82)
(BC = a) (AC = b) & (AB = c)
a^2 = 529 +441 − 966*0.139173101
a^2 = 970 − 138.6164086
[tex]\sqrt{a^2}[/tex] = [tex]\sqrt{835.5587845}[/tex]
a = 28.9060337 which rounds to 28.9
