Question

If distinct planes R and S are both perpendicular to line L , which is always true?

1. Plane R is parallel to plane S
2. Plane R is perpendicular to plane S
3. Planes R and S and line L are all parallel
4. The intersection of planes R and S is perpendicular to line L

Answer 1

Option 1 is correct.

Explanation:

Let there is a line A which is perpendicular to line L at point O.

Now, rotating line A about point O by 360° will give the plane R.

So, plane R is perpendicular plane to line L.

Again, let there is a line B which is perpendicular to line L at point P.

Now, rotating line B about point P by 360° will give another plane S.

So, plane S is perpendicular plane to line L.

Since line A and line B are parallel (As they are perpendicular to the same line L) so, plane R containing line A and plane S containing line B will also be parallel to each other.

Hence, option 1 is correct. (Answer)