Answer: Choice B) 4/5
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Step-by-step explanation:
The side opposite angle A is BC = 8. This side is as far as you can get from angle A.
The hypotenuse is the longest side, and always opposite the 90 degree angle. The hypotenuse is AC = 10.
We can then say,
sin(angle) = opposite/hypotenuse
sin(A) = BC/AC
sin(A) = 8/10
sin(A) = (4*2)/(5*2)
sin(A) = 4/5 which points to choice B as our answer.