Answer:
Approximately 19 units.
Step-by-step explanation:
The question asks for an estimate, so this is an estimate.
The bottom side has a length of 4.
The two sides that go up from the bottom are diagonals in 1 by 3 rectangles.
Each side is between 3 and 4 units long. Call it approximately 3.5 units long each.
The two upper sides are diagonals in 3 by 3 rectangles.
Each side is approximately 4 units long.
4 + 3.5 + 3.5 + 4 + 4 = 19
