Okay making a mid-century modern cleat bracket that’s angled (A.K.A splayed) only has one tricky bit and then everything else is easy.
For your measurements, you want your length to be about 8 inches less than the width of whatever object you’re putting it on. So if you’re putting it on a table, you want the cleat to be 8 inches less than the width of your table (it should be perpendicular to the length of the table). The width of your cleat should be about 2 ½” to 2 ¾” inches. The depth is going to be somewhere between 1 ¼” to 1 ⅜”. That gives you enough space to put in your inset screws and screw in your legs. You’ll also want to pre-drill the holes for attaching your cleat to your table before making the following cuts.
Now the tricky bit is that you have to cut two angled cuts simultaneously. Doing them separately is far too difficult. The cuts are 11 degrees and 15 degrees. This is best done on a miter saw, because you can cut two angles at the same time. The way you do it is you set the regular miter gauge (the one you have on the front that lets you go right and left) to 11 degrees, and then tilt your piece to 15 degrees.
The 15 degree cut is the trickier of the two angles. To pull it off, you’ll want to make a 15 degree cut on a scrap piece of wood, which will become your stop block. Use your mitre saw to do the 15 degree cut, then set it back to 11 degrees.
That to 11 degrees and then cut actually set that to 15 degrees first get a scrap piece of wood cut that piece of wood at 15 degrees, so you’re making yourself a 15 degree stop block. Then set it back to 11 degrees
Set up your cleat up against the 15 degree stop block so it’s actually leaning against it and hold it there with a push block or gripper (I used one of these). Do not hold it with your hands or you’ll potentially chop your fingers off! So use something to hold it in place that will keep you safe and then line up the 11 degree cut so that it starts about 3/8 of an inch off the side of your board that’s going to be attached to your table. See photo for better explanation.
So you’re cutting along the length of your cleat at this point. 11 degrees on the miter saw with a 15 degree lean up against your stop block. That will give you the two angles that you need, the 11 and the 15, to be able to make the correct cut on your cleat. Note: you will be cutting slightly into your stop block, so you’ll need to make a new 15 degree cut when you cut the opposite ends of your cleat. Repeat that cut for each of your cleats, then reverse the set up for the other end of your cleats. Meaning, make a new 15 degree stop block and swing your mitre gage to 11 degrees on the opposite side. Then do the same thing you just did, but in reverse.
That’s how you get the angles you need!