Answer: What Comes Next? #214

The answer is B: an arrow pointing up and right.

The finished pattern: an arrow pointing down and right, an arrow pointing down and left, an arrow pointing up and left, an arrow pointing up and right, an arrow pointing down and right, an arrow pointing down and left, an arrow pointing up and left, an arrow pointing up and right.
The finished pattern.

The rule

The arrow turns 90 degrees clockwise (the way a clock’s hands move) every time. A quarter turn is 90 degrees, so it takes 4 steps to point the same way again.

The pattern as Python code

Here is a tiny Python program that follows the same rule. Type it into IDLE and run it to print the whole pattern, including the answer.

direction = 135
for step in range(8):
    print("Step", step + 1, "points", direction, "degrees")
    direction = (direction + 90) % 360

When you run it, Python prints:

Step 1 points 135 degrees
Step 2 points 225 degrees
Step 3 points 315 degrees
Step 4 points 45 degrees
Step 5 points 135 degrees
Step 6 points 225 degrees
Step 7 points 315 degrees
Step 8 points 45 degrees

Pixel says: Try changing a number in the code and run it again. Can you make the pattern go on for 20 steps? Meow!