Answer:
A ≈ 67°
Step-by-step explanation:
Since you have all three sides of the right triangle, you can use any of the inverse trig functions to find the angle. SOH CAH TOA reminds you ...
Sin(A) = Opposite/Hypotenuse = 12/13
A = arcsin(12/13) ≈ 67°
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Cos(A) = Adjacent/Hypotenuse = 5/13
A = arccos(5/13) ≈ 67°
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Tan(A) = Opposite/Adjacent = 12/5 = 2.4
A = arctan(2.4) ≈ 67°
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Comment on calculator use
When you use your calculator for these inverse functions, make sure it is in "degrees" mode (not "radians"). Your calculator keys may be labeled with a "-1" superscript to indicate the inverse function. You can use the rounding function of your calculator, or you can round the number yourself (probably easier).
sin⁻¹ = arcsin
cos⁻¹ = arccos
tan⁻¹ = arctan
A Google search box is also capable of showing you the inverse trig function value. (see attachment)
