A circle has a radius of 5 centimetres. Enter the number of centimetres in its diameter.
Respuesta correcta
10 · Unidades aceptadas: centimetres · cm
Explicación
Two lines from the centre laid end to end across the middle stretch the full width of the circle, so that width is 5 doubled. Entering 2.5 halves the given measurement instead, which describes a distance shorter than the radius itself and could never span the circle.