by David Finnerty

8th Grade
General Math

Plotting Points, Angles, & Reflections

David Finnerty
To obtain a downloadable copy of the worksheet that accompanies this bulletin board, click on the button below.

TITLE: Hole in 1

SUBJECT: 8th Grade General Math

TOPIC: Plotting points, angles, & reflections

INTERACTIVITY: Students are asked to identify the correct aiming point for each hole by reflecting an image of the ‘Hole’ about the axis determined by the rail of the miniature golf hole.


  1. Take an Activity Sheet from the pouch below. Select ‘Hole’ 1 from the pouch below and place ‘Hole’ on the center of the grid as indicated by the black Velcro.
  2. Select a ‘Ball’ from the pouch and snap ‘Ball’ into position indicated by the yellow circle.
  3. Since the direct path to the hole is blocked, select a rail to play a bank shot.
  4. Count the number of grids from the center of the ‘Hole’, indicated by the gray circle, to the selected rail. (In the example above, the hole is 3 grids from the rail.)
  5. Continue counting the same number of grids past the hole. Call this point Hi. The rail should be exactly halfway between the center of the ‘Hole’ and point, Hi. Point Hi is an image of the hole reflected over the axis determined by the rail. (In the example above, Hi is 3 grids from the rail.)
  6. Hi is your aiming point for your bank shot. To shoot, place the Hi button attached to the ‘Ball’ at point Hi. (You may need to replace your ‘Ball’ if the selected ‘Ball’ is not long enough.)
  7. In miniature golf we know if we correctly selected Hi when the ball goes into the hole. To check if you correctly selected Hi, you can reflect the ‘Ball’ over the same rail. Leave your ‘shot’ in place. Snap the ‘Hole’ into the gray circle. Reflect the ‘Ball’ about the axis determined by the rail. Call this point, Bi. Place the Bi button, attached to the ‘Hole’, at point Bi. If the lines intersect at the rail, congratulations you made a hole in one! If the lines do not intersect at the rail, check your Hi and Bi positions and try again.
  8. Continue with Holes 2 & 3 and try for more holes in one!

TIME: 10 minutes

SPECIAL CONSTRUCTION: Grid was constructed using 6-strand embroidery thread wound around thumbtacks placed at one inch intervals. Backing for grid is fabric that accepts male hook & loop fasteners. ‘Ball’ and ‘Hole’ buttons are laminated paper circles 1" diameter and attach to the hole with snap fasteners. Hole image, ‘Hi’, and Ball image, ‘Bi’, buttons are similarly constructed replacing the snap fastener with a 5/8" male hook & loop. Each ‘Ball’ button is connected to an ‘Hi’ button with 3/8" elastic similarly, each ‘Hole’ button is connected to a ‘Bi’ button. An additional ‘Bi’ to ‘Hi’ tandem with male hook & loop fasteners is used for double reflections.

CREDIT: The bulletin board was designed as an extra credit project.