Question: On a cuboid with a length of 4cm, a width of 1cm and a height of 2cm, an ant climbs from vertex A to vertex B. What is the shortest path for an ant to climb? (A is in the upper left corner and B is in the lower right corner)

Answer: Put a rectangular plan of Zhang Kaicheng.

Then connect these two points.

There are two ways: one is to intersect with a 2cm edge, and the other is to intersect with a 4cm edge.

Calculate by Pythagorean theorem respectively

(2 * 2+5 * 5) 0.5 = 29 0.5, which is the root number 29.

(3*3+4*4)^0.5=5

29^0.5>； five

So the shortest is 5cm.

Climb forward first, intersect with the edge of 4cm, and then climb down.