Find the angles of the parallelogram ABCD if the angle A is 40 degrees and the angle C is 25 degrees.

The condition is incorrect, because in a parallelogram, opposite sides are equal and opposite angles are equal.

Let’s solve the problem based on the fact that the angle A is 40 degrees.

∠A and ∠B are internal one-sided. The sum of the inner one-sided angles is 180 degrees. Then:

∠А + ∠В = 180 °;

∠В = 180 ° – ∠А;

∠В = 180 ° – 40 °;

∠В = 140 °;

∠А = ∠С = 40 °;

∠B = ∠D = 140 °;

Answer: ∠А = ∠С = 40 °; ∠B = ∠D = 140 °;

Let’s solve the problem based on the fact that the angle C is equal to 25 degrees.

∠C and ∠D are internal one-sided. The sum of the inner one-sided angles is 180 degrees. Then:

∠C + ∠D = 180 °;

∠В = 180 ° – ∠А;

∠D = 180 ° – 25 °;

∠D = 155 °;

∠А = ∠С = 25 °;

∠B = ∠D = 155 °;

Answer: ∠А = ∠С = 25 °; ∠B = ∠D = 155 °