Answer:
3 1/6. Hope this helps :)
At least one right angle:
A + C + E
At least 2 sides of equal length:
B + C + E
At least one pair of parallel sides:
A + B + E
Let the water surface be 0.
He starts at 15 and gets to the water surface of 0 so he travels 15 meters.
He then goes 5 meters below the surface.
15 + 5 = 20 total meters.
