When two straight lines intersect, four undeveloped corners are formed. One of them is 20 degrees smaller than the other.

When two straight lines intersect, four undeveloped corners are formed. One of them is 20 degrees smaller than the other. Find the degree measures of all four angles.

To solve this task, you must remember that the sum of adjacent angles is 180 °;
Also, for convenience of explanation, we will designate the unknown angle X, then the second angle will be “X + 20 °”
Having this data, we can make the following equation;
180 ° = X + X + 20 °;
Let’s give similar terms and get;
180 ° = 2X + 20 °;
2X = 180 ° – 20 °;
2X = 160 °;
X = 160 ° / 2;
X = 80 °;
Knowing what one of the angles is equal to, we find what the adjacent angle is equal to and obtain the expression;
80 ° + 20 ° = 100 °;
Answer: when straight lines intersect, angles of 80 ° and 100 ° are formed.