Web Apps Acceleration Measure and plot acceleration with this app. Please lock your screen orienatation before using this app. Colour Display Understand how light works when you add colours together. Listen Measures frequency of sound. You can set the range. Currently does not work in iOS. Measure Measure distance, angles, and area. If you are on a mobile device, please lock your screen orienatation before using this app. Pythagoras Learn where the pythagoras formula comes from. If you are on a mobile device, please lock your screen orienatation before using this app. Sine/Cosine Understand where sine and cosine come from. If you are on a mobile device, please lock your screen orienatation before using this app. Sound Creates soundwaves of particular frequency. Works best on Firefox and Chrome. Currently does not work in iOS. Web Tracker Shows the velocity, position, and acceleration of an object in real-time. Works best on a laptop with an external webcam.