triangle = tri(三) + angle(角) = 三个角→三角形
triple = tri(三) + ple(重叠) = 三倍的
motocycl = moto(动) + cycl(圆) = 摩托
cycl = cycl(圆) = 绕着圆圈转→循环
One report tells of a totally blind boy who could ride his tricycle at good speed round the block near his home, using facial vision.
Our son has just graduated from a tricycle to a proper bicycle.
A tricycle was in my way.
A tricycle has three wheels.