Question

You are constructing a railing to place on a ramp for your handicapped grandmother. You have been given a 12-ft rail and 5 posts to support the railing. The posts are equally spaced under the rail and the first and last posts are positioned at each end of the rail. The ramp rises at an angle of 12°.

a. What part(s) will represent the transversal(s)?

b. In order to make the posts parallel, what angles must they form with the transversal?

c. What angle would they form with the ramp?

d. Which angles would be alternate interior, alternate exterior, corresponding, and consecutive interior? Explain your reasoning.

e. What do you know about each of these angles?

f. How far apart will the posts be?

Answer 1

a. The railing is transversal to the posts

b. In order to make the posts parallel, the angle between the posts and the transversal should be = 78°

c. The angle between the post and the ramp is 102° as we reach the post from the bottom and 102° and 78° immediately after the post

d. 1) Alternate interior angles = 78° and 102°

2) Alternate exterior angles = 102°

3) Corresponding angles = 78° and 102° depending on the side of from which we approach the post

4) Consecutive interior = 78° and 102° depending on the side of from which we approach the post

e. The interior angles are supplementary

f. Horizontal spacing between posts = 2.93 ft.

Spacing between posts along the length of the railing = 3 ft. spacing

Explanation:

a. A transversal is a line crossing two or more parallel lines which are in a plane at different points

Therefore, the railing is transversal to the posts

b. Whereby the ramp rises at an angle of 12°, the railing, which is the transversal is therefore inclined at 12° to the horizontal and the posts which will be vertical erect will be at 90° to the horizontal

Therefore, in order to make the posts parallel, the angle between the posts and the transversal should be 90° - 12° = 78° for each post to railing.

c. The angle between the post and the ramp before the post as we ascend the ramp is therefore, 180 - 78 = 102° and 78° after the post

d. The alternate interior angles lie on the opposite sides of the transversal = 78° on one side and 102° on the other (Sum of angles on a straight line) which are the angles on the transversal

The alternate exterior angles lie on the exterior opposite sides of the transversal = 102°

Corresponding angles are the angles located in the corresponding positions on the transversal = 78° on one side and 102°as we cross the post (Sum of angles on a straight line)

Consecutive interior angles are the angles that are located on the same part of the transversal = 78° and 102° (Sum of consecutive interior angles of parallelogram = 180°

e. For the posts to be parallel, the consecutive interior angles should be supplementary or equal to 180°

f. Whereby we have a 12-ft rail inclined at 12°, we have;

Horizontal distance covered by the rail = 12 × cos(12) = 11.74 ft

Since we have 5 posts, there 4 equal spaces between them which gives

Spaces between posts = 11.74/4 = 2.93 ft. horizontally and 3 ft. spacing between each post along the railing.