Write the next sentence in this paragraph:

How to build and use a pendulum
Collect your materials.
This pendulum experiment is easy to do at home. All the materials should be readily available.

OPTIONS:
[i] Make sure you have all the materials ready, though. Depending on the measurements taken, you can either use a compass to calculate the item's direction, or use a ruler to figure out where the pendulum will hang..
[ii] For example, you'll need a watch, clock, a ruler, a table clock, and a medium-sized right hand pendulum. You will need some sturdy crossing cords, as well as something suitable for gardens, cabins and other areas..
[iii] For the purposes of this article you'll only be doing one pendulum, but you can cut more of different lengths, so make sure that your length of string is over 70 centimeter (27.6 in). Gather two chairs and a meter stick..
[iv] At a hardware or home improvement store, see the tools section for help. Cut a circle out of scrap wood..
[iii]