Question

determine if each statement is always, sometimes, or never true
1 parallel lines are coplanar
2 perpendicular lines are coplanar
3 distance around an unmarked circle can be measured
always
sometimes
never

Explanation:

1. Parallel lines by definition lie in the same plane (coplanar).
2. Perpendicular lines intersect and thus lie in the same plane (coplanar).
3. For an unmarked circle, if we can measure its radius or diameter (e.g., by using a string to measure the circumference indirectly), it can be measured. But if we have no tools or methods to relate to its size - related parameters (like no way to find radius/diameter), it can't be measured. So it's sometimes true.

Answer:

1. always
2. always
3. sometimes