There are three 90 degree angles. (Looking at home plate from a "pitcher's viewpoint), the wide "front" of home plate has 90 degree angles on both sides. The back point, e.g. "the heart of the plate," is also a 90 degree angle. The two angles closest to the batter's back foot are both 135 degrees. This is because these angles are the sum of a 90 degree angle and a 45 degree angle. The back "triangle" of home plate is a 45-45-90 triangle. Hope this helps.

Tonga

• You put your knife and fork side by side across the plate.
  

Direction of helicopter changes slightly

it is about 375