Working: We need to use inverse trigonometric functions to evaluate the angle Note that tan(Θ)=o/a where o=opposite side & a=adjacent side (the last being the hypotenuse) The inverse being Θ=arctan(o/a) We substitute the given sides to get Θ=arctan(4/4.1) Put this into the calculator and the result is ≈ 44.2926806315 Rounded off to 2 decimal places: Θ≈44.29 N.B. arctan usually appears on a calculator as tan to the power of -1
