Find the angles of the rhombus if one of its diagonals makes an angle of 70 with the side.

A rhombus is a parallelogram in which all sides are equal and the angles are not right.

In a rhombus, the opposite angles are equal:

∠А = ∠С;

∠В = ∠D.

The diagonals of a rhombus are also bisectors of its corners (they divide the corners of a rhombus in half):

∠В = ∠АВD + ∠СВD;

∠A = ∠BAС + ∠DAС;

∠А = 70º + 70º = 140º.

Since the sum of the angles of a rhombus adjacent to one side is 180º,

∠В = 180º – ∠А;

∠В = 180º – 140º = 40º.

∠С = ∠А = 140º.

∠D = ∠В = 40º.

Answer: angles ∠С and ∠А are equal to 140º, angles ∠D and ∠В are equal to 40º.