Compound Measures (Speed, Density, Pressure)

Two quantities combined into one measure — master the triangles and you can find any missing value.

Density, Mass & Volume

Learn the density-mass-volume formula, how to use the triangle, and why units like g/cm³ mean exactly what they say.

Pressure, Force & Area

Understand pressure as force spread over an area — use the triangle to find any missing quantity and get the units right every time.

Speed, Distance & Time

Use the speed-distance-time triangle to find any missing value — with tips on units and the most common exam traps.