One really important thing that should be noted beforehand is that the angles in this case are measured in degrees, not in radians.
In a right-angled triangle there are three angles: one which is 90 degrees and the sum of the other two adds up to 90 degrees to give 180 overall. For the sake of the argument, let us call the angles that are acute as they are less than 90 degrees, angles A and B.
If we change the value of the Angle A that will also alter the value of the Angle B, the Adjacent Side's length, the Hypotenuse and consequently the Area of the triangle. Similarly for angle B; if we change the value of the Angle B, this will alter the value of Angle A, the Opposite Side's length, the hypotenuse and the Area of the triangle.
The adjacent side of an angle is the side that forms that particular angle with the hypotenuse and the opposite side is just opposite to the given angle.
The Pythagoras Theorem states that sum of the squares of the adjacent and the opposite sides is equal to the square of the Hypotenuse.
Formula: c2 = a2 + b2 ,where a = Adjacent side, b = Opposite side, c = Hypotenuse
If we change the Opposite Side's length which is measured in units without clarifying the exact units, i.e. cm, m etc., this will alter the value of the both angles A and B as well as the Hypotenuse and the Area of the triangle.
If we change the length of the Adjacent Side, this will change the Angles A and B, the Hypotenuse and the Area of the triangle.
Lastly, if the length of the Hypotenuse is changed, then this will alter the Opposite Side's length as well as the Adjacent Side's length and consequently the Area of the triangle.
The final note is that the number of decimal places to which the calculations are carried out is preset to be 2, but it can be changed by the user.