In a rhombus ABCD where O is the intersection point of BD and AC, angle BAO = 70 °, find the angles COD.

The diagonals AC and ВD of the AВСD rhombus intersect at right angles. The diagonals also divide the corresponding angles into equal angles.
If ∠BAC = 70 °, then ∠OAD is also equal to 70 °.
Find ∠ВAD and ∠ВСD:
70 ° + 70 ° = 140 °.
The sum of all the angles of the rhombus is 360 °. Let us find ∠ABС and ∠ADС:
(360 ° – 140 °): 2 = 220 °: 2 = 110 °.
Let’s find ∠ADС:
110 °: 2 = 55 °.
СOD angle = 90 °.
∠ОСD = ∠ВАC = 70 °.
ANSWER: ∠ОСD = 70 °, ∠СAD = 90 °, ∠ОDС = 55 °.