circular saw

Cutting in place grab a circular saw and speed square.

I'd do that with a circular and/or miter saw.

the miter saw and circular saw are the way to do it

Miter saw/circular saw for cutting 80/20 to length. Circular saw will give a much neater window opening than trying anything with a jigsaw.

Track saws are great, but you can get absolutely equivalent results with ANY circular saw with a little care in setup and anything with a straight edge.

Circular saw with a 48” straight edge and a 4 pack of squeeze clamps, as well as a 7” carpenters edge can do almost 80% of what you need.

Even the cheapest circular saw will leave a clean cut.

There are few tools of similarly small stature that are anywhere near as versatile.

You can do a surprising amount of nice work with a circular saw, straight edge, and a couple clamps.

Parent context: You prob have a circular saw? Fine tooth blade would be the way to go. Reply: That dull plywood blade you have sitting around would do the trick nicely.