Answer:
b. The measure of angle 1 is 90°.
c. The lines are perpendicular.
d. Angle 1 is a right angle.
Explanation:
Perpendicular lines are connected to right angles.
Right Angles
Right angles are 90° angles. Oftentimes, these angles are denoted by a square drawn near the vertex. As you can see in the image, angle one has a square drawn in the vertex, which shows that it is a right angle. This means it has a measure of 90°.
Right angles are not considered acute or obtuse. Instead, a right angle is its own category.
Perpendicular Lines
Perpendicular lines are lines that form right angles at the intersection. Since angle 1 is a right angle, the lines must be perpendicular. Additionally, when perpendicular meet, all 4 angles created are right angles. This means the other 3 angles shown are also right angles.