Math Saved My Porch

By Dara


Math tags: algebra, geometry, trigonometry

Other tags: construction, carpentry

We discovered that we had a ground subsistence problem under the porch on the north side of our house one day - moles had dug the soil out from under the supports - and I needed to build some emergency supports that went out to the side to hold it up while we brought in some gravel. To do that, I needed to figure out the angle at which the temporary supports would have to attach in order to reach the solid ground nearby, and how long they would need to be. I couldn't just measure it, because it was a second storey porch and the diagonal was too long.

The easiest answer turned out to be to use the parts of the _right triangle_ I could measure (distance on ground, and distance up) and trigonometry to calculate the length of the diagonal beams (or hypotenuses) and angles of attachment, then cut them on the ground and hoist them into place. As it turned out, I didn't even have to make a run to the lumber yard - I was able to figure out (with math!) I had enough pieces left over from another project.

If this sounds like a word problem, I thought of that at the time, and was telling everybody, "Hey, I just used trig to fix my porch!"