Some measurements

 Non-standard measures:  The lengths of steps, arms, hands, or fingers of different people are different, therefore the distance measured with their help is not always     reliable. These methods are, therefore, called non-standard measures.

 The lengths of steps, arms, hands, or fingers of different people are different, therefore the distance measured with their help is not always reliable.

 These methods are, therefore, called non-standard measures. While measuring things, accuracy is needed.

  A variety of units can be used for this purpose.