how to evaluate sin(a) when adj =4 and oposit side 10?

Answer 1

find hypot ... √(4^2 + 10^2)

sin = oposit / hypot = 10 / √(4^2 + 10^2)

Answer 2

since adj^2 + opp^2 = hyp^2

and sin = opp/hyp

in this case, sin(a) = 10/√(10^2+4^2) = 10/√116