Barney

By

Tennille Rushin

Barney
is in the triangular room shown here. He walks from a point on AC parallel to
BC. When he reaches AB, he turns and walks parallel to AC. When he reaches BC, he
turns and walks parallel to AB. How many times will Barney reach a wall before
returning to his starting point?

First let’s construct a GSP sketch. Construct a triangle and label the
vertices A, B, and C. Then place a
point on segment AC and create a parallel line to segment BC. Create a second point at that
intersection and make a parallel line to AC. Create a third point and parallel line to AB. Use the fourth point to create a
parallel line to BC. Take the next point and create a parallel line to point
AC. Use the last point to make a
parallel line to AB. This will
complete your path.

Click here
to open a GSP file