Which one is a method of dimensioning :

Explanation:

Aligned Dimensioning:

1. The dimensions lines are drawn parallel to the object lines.
2. The dimensions values are placed above the dimensions lines and not by breaking the dimensions lines.
3. The dimensions values are placed near the middle and clear of the dimensions lines.
4. All dimensions are so placed that they can be read from the bottom or the right hand edge of the drawing sheet.
5. It is used in Engineering drawings.

Additional InformationUnidirectional Dimensioning:

1. The dimensions lines are drawn parallel to the object lines. 
2. The horizontal lines are dimensioned as in the above method.
3. Vertical and inclined lines are dimensioned by writing the value of the dimension in the gap left in the middle of the dimensions lines.
4. All dimensions are so placed that they can be read from the bottom of the drawing sheet.