The diagonals of Square ABCD meet at point O. Determine the angles of the triangle COD.

Given a square ABCD, this means that angles A, B, C, D are straight (equal to 90 °), sides a, b, c, d are equal, that is, a square is a rhombus in which all corners are straight.

The diagonals of the square AC and BD (as well as the rhombus) are perpendicular, that is, when they intersect, they form right angles with the vertex O:

The COD angle is 90 °.

The diagonals of the square (as well as the rhombus) divide the angles in half, so the angles OCD and ODC are equal to each other (angle C is equal to the angle D by condition):

OCD = ODC = 90 °: 2 = 45 °.

The angles in the COD triangle are 90 °, 45 °, 45 °.