The problem asks to find the values of the angles marked with letters in two diagrams.
GeometryAnglesLinear PairsVertically Opposite AnglesParallel LinesAlternate Interior AnglesCorresponding AnglesSupplementary Angles
2025/4/1
1. Problem Description
The problem asks to find the values of the angles marked with letters in two diagrams.
2. Solution Steps
Problem 1:
We are given that one angle is and another is . We need to find .
Since and form a linear pair, we have:
Since and form a linear pair, we have:
Angles and are vertically opposite angles, so .
Angles and are vertically opposite angles, so .
Angles and are vertically opposite angles, so .
Angles and are vertically opposite angles, so .
Problem 2:
We are given an angle of and an angle of . We need to find .
We are given that the lines are parallel.
Since the angle and form a linear pair, we have:
Since the lines are parallel, alternate interior angles are equal. So .
Since the lines are parallel, corresponding angles are equal. So .
Since the lines are parallel, and are supplementary angles.
. However, this is not angle . Since line 2 and 3 are parallel, the angle vertically opposite to (call it ) and the angle are supplementary. Therefore,
.
.
and are vertically opposite, so .
and are vertically opposite, so .
3. Final Answer
Problem 1:
Problem 2: