The sum of the two angles of a parallelogram is 100 degrees. Find all the angles of the parallelogram.

1. A, B, C, D – the tops of the parallelogram. ∠А + ∠С = 100 °.

2. In a parallelogram, the angles opposite each other are equal. ∠А = ∠С = 100 °: 2 = 50 °.

3. According to one of the properties of a parallelogram, the total value of the angles on one side is 180 °. Using it, we calculate the degree measure ∠В:

∠В = 180 ° – ∠А = 180 ° – 50 ° = 130 °.

4. ∠Д is also equal to 130 °, since it is opposite to ∠В.

Answer: ∠А = ∠С = 50 °, ∠В = ∠D = 130 °.