Stephanie M. answered 05/19/15
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Usually when we talk about an angle being across from something in a triangle, it's across from a side, not another angle. So, it's not quite clear what angles x, y, and z represent, but I'll make my best guess. I'm assuming:
x is across from the 28-unit side in Triangle 1
y is across from the blank side in Triangle 2
z is across from the 77-unit side in Triangle 2
We'll use the Trigonometric functions to solve for x, y, and z.
x:
x is across from 28 and adjacent to 45. So, use tangent:
tan(x) = opposite/adjacent
tan(x) = 28/45
x = tan-1(28/45)
x = 31.89°
y:
y is adjacent to 77 and the triangle's hypotenuse is 85. So, use cosine:
cos(y) = adjacent/hypotenuse
cos(y) = 77/85
y = cos-1(77/85)
y = 25.06°
z:
z is opposite 77 and the triangle's hypotenuse is 85. So, we could use sine, or we could remember that a triangle's angles add up to be 180°. So:
90° + y + z = 180°
90° + 25.06° + z = 180°
115.06° + z = 180°
z = 64.94°