Question

Wondering how to solve n the steps

Answer 1

Check the picture below.

well, we know those sides are twins, the ones with the tickmarks, so in an isosceles triangle, twin sides make twin angles, so in this case we have the twin angles of ∡z and ∡w made by those twin sides, so whatever the third angle in that triangle may be, it must be 180 minus the other two angles, as you see in each triangle for each.

Those two angles at point E are linear angles, namely angles sitting on a flat-line, so their sum will be 180°, thus we can say that

`(180-2z)~~ + ~~(180-2w)~~ = ~~180\implies 360-2z-2w=180 \\\\\\ 180-2z-2w=0\implies 180=2z+2w\implies 180=2(z+w) \\\\\\ \cfrac{180}{2}=z+w\implies 90=z+w`

so since ∡z and ∡w are complementary angles, the angle across ∡z is 90°, and so on.