Explanation

At its simplest all trigonometry is is how the ratio of the lengths of different sides of a right angle change when an angles changes.

This tool shows a triangle that is forced into being a right angled triangle no matter how much you drag or squeeeze it.

Its lengths can be altered by dragging one or other of the circles on 2 of its corners.

If it becomes too big or small after dragging these corners it can be zoomed by right clicking or left clicking and scrolling with a mouse.

The angle can be adjusted at 1 degree increments by use of the slider at the top left.

At any given time only the 2 lengths appropriate to the selected trigonometric function (sin, cos or tan) are shown.

Whenever any changes are made to the triangle the length and angle measurements changes show on both the triangle and in the calculation near the top of the screen.

Need to see another trig function calculation just click one of the other two functions checkboxes near the top.