Trig Practice (Unit Circle background)
Try showing the circle and axes to emphasise the unit circle origins of the diagram.
OR
Hide the circle and axes, and leave two bits of information (side and an angle? two sides?), see if you can calculate the rest.
This works best with A in the first quadrant (otherwise the angle will not be an internal angle of the triangle)
The hypotenuse changes with the slider at the top left.