The intersection d is the perpendicular of EF, and the vertical foot is g.

Because ABCD is square, BD//CF

So ∠DCF=∠BDC=45 degrees

So the triangle DCG is an isosceles right triangle.

So DC=√2DG

And because the triangle BDC is an isosceles right triangle.

So BD=√2DC

So DB=2DG.

Because BDFE is a diamond.

So DF=DB=2DG.

And because DG is perpendicular to GF.

So ∠2=30 degrees

Because BDFE is a diamond.

So ∠ 1= 150 degrees.

So < 1 = 5 < 2.