Please choose the correct ending to complete the given sentence: Home and Garden: [header] How to measure bends when bending pipes [title] Estimate the overall length of the pipe. [step] Depending on the length of the bends and the length of the spaces between them, determine the total length of pipe or tubing you require. Ensure that a couple of inches (or centimeters) of margin is available to accommodate any errors in calculation or judgment.

Ending1: [title] Measure the distance for the first bend. [step] From one end of the tube, mark the point for the first bend. Ending2: [substeps] As stated above, any bends to the pipe are only for measured by measuring its very length. If a bend isn't necessary, just continue to estimate. Ending3: [title] Calculate the standard density of the pipe or tubing you will need. [step] Calculate the ideal density for each bends of the pipe. Ending4: [title] Measure the angle in the space between the bend and the total length of the pipe. [step] Use your free hand to draw the pencil line and measuring tape along the angle.

Answer format: ending1/ending2/ending3/ending4