The two corners have correspondingly parallel sides. One angle is 40 degrees larger than the other. Find the smaller angle.

As the rule says: if the corresponding sides of two corners are either parallel or perpendicular, then these angles are either equal, or the sum of these angles is 180 degrees.

Since one of this pair of angles is 40 degrees larger than the other, it is obvious that these angles cannot be equal. This means that the smaller angle is denoted by x, and the larger one – by x + 40. We get the equation:

x + x + 40 = 180;

2 * x + 40 = 180;

2 * x = 180 – 40;

2 * x = 140;

x = 140/2;

x = 700 is a smaller angle.

Answer: The smaller angle is 70 degrees.