The 3D design program Google SketchUp has at least two ways for users to enter dimensions. One is through typing a dimensioning figure either during or immediately after you draw a shape such as a line, rectangle or circle. Another way is by using the mouse together with the Dimension tool. With the first approach, you can enter dimension figures in any common unit such as inches, feet or meters. The units of the second approach are in inches by default.
Open SketchUp, then click the toolbar's "Line" tool.
Drag a short distance. SketchUp displays a text box showing the length of the line.
Type "40'" to extend the line to 40 feet.
Type "40"" to shrink the line to 40 inches. You can enter other common units of measurement, such as "cm" for centimeters and "m" for meters.
Press "Enter" to finish the line.
Click the "Rectangle" tool on the toolbar, then drag on the ground plane to define the rectangle.
Click to finish the rectangle, then type any two numbers separated by a comma. For example, type "20",40"" to specify a rectangle measuring 20 by 40 inches. As with the line drawing, you can specify abbreviations for common units.
Click the toolbar's "Circle" tool, then drag to define the circle, followed by clicking to finish this shape.
Type a dimension number as you did for the previous shapes. This number tells SketchUp what radius to draw the circle to.
Use the Dimension Tool
Open SketchUp, then click the "Rectangle" tool on the toolbar.
Drag on the ground plane to grow the rectangle, then click to finish the rectangle.
Click the "Tools" menu heading, then click the "Dimension" item in that menu.
Click the end of one edge of the rectangle you drew in Step 2, then click the other end. This tells SketchUp that you want the Dimension tool to display the length of the selected edge. That length now appears atop the edge.
Drag the mouse away from the rectangle. The dimension text follows the cursor. This action lets you pull the dimension text away from the object it's measuring, which is essential for clear drawings.
Click the mouse to finalize the dimension label.
Press "Space" to pick up the Selection tool, then click an edge of the rectangle adjacent to the one you applied the Dimension tool to.
Click the toolbar's "Move" tool, then drag the selected edge to move it. The Dimension tool's text automatically changes to reflect the current length of the edge it's measuring. This means that you can enter precise measurements by using the Move tool with the Dimension tool.