23 October 2014

Angles - cube problem

1. What angle is made by the two red lines drawn on the two sides of the cube, as shown in the illustration?
cube 1

Answer...
If the ends of the two red lines at the bottom left and top left are connected by a third red line along the invisible left face of the cube, then since each of the red lines joins two opposite corners of same-sizes squares, those three lines form an equilateral triangle. Hence at each corner of that triangle, two red lines meet at 60 degrees.
cubes 2

7 comments:

  1. With a protracter we mesured our self-drawn cube. The result was 45º

    ReplyDelete
  2. With a protracter we mesured our self-drawn cube. The result was 65º

    ReplyDelete
  3. This comment has been removed by the author.

    ReplyDelete
  4. With a protracter we mesured our self-drawn cube. The result was 50º

    ReplyDelete
  5. Hint - join the red lines then measure...

    ReplyDelete
    Replies
    1. not the best hint rob we have done that

      Delete
  6. With a protracter we mesured our self-drawn cube. The result was 60º

    ReplyDelete