In many textbooks concerned with relative measurements in the special theory of relativity, the length of a uniformly moving rigid body is calculated on the basis that the coordinates of the two ends of the body are to be determined simultaneously. The present paper shows that, for this simple problem, it is both possible and physically more meaningful to make such a determination nonsimultaneously by taking into account the fact that light signals require a finite time to propagate. The basic idea of nonsimultaneity is extended to the calculation of the Doppler shift of light frequency, giving the usual relativistic result.