Isometric grid set at 26 degrees

[gwpriester]

Just because I am dense, and inquisitive, but why would you want the grid to be at 26 degrees instead of multiples of 15?

Isometric grids and drawings are a simple method of simulating 3D perspective without the tedious vanishing points etc.

[covoxer]

Because it is easy to draw on the graph paper. See attached.
This was not invented by Xara but was used for many years and possibly was even more often used than the true isometric.
And it's not 26° but atan(0.5) ~ 26.565051177077989351572193720453°...

[handrawn]

[cursor]

And it's not 26° but atan(0.5) ~ 26.565051177077989351572193720453°

For fun, I'll add the following equivalents.

[Soquili]

Curtis either my calculator is broken or your formulae are inaccurate.

[cursor]

They work fine for me, Bill. Note that the symbol prior to the square-root-of-five is a division symbol, not a plus sign.

[cursor]

Considering covoxer's graphic above, the slope of the line is 1:2. Given that a² + b² = c², c, the hypotenuse would be the square root of 5.

The angle could be expressed as tan(a/b), sin(a/c), and cos(b/c).

[Soquili]

Curtis larger size doesn't change the formula, the sine of 1 divided by the square root of 5 does not yield anything near 26.565051177077989351572193720453°

The square root of 5 is 2.2360679774997896964091736687313
1 divided by 2.2360679774997896964091736687313 equals 0.44721359549995793928183473374626

Sin(0.44721359549995793928183473374626) equals 0.0078052704465482364130100178763261

The CoSine of 2 divided by the square root of 5 equals 0.99987815550651248138827984630394

Neither are equal to 26.565....

[gwpriester]

I'm really sorry I asked. I did not think that slide rules would be needed.

[steve.ledger]

My head hurts...