Problem number 19. A pyramid is built out of cubes. Each cube has a side length of 10 cm. An ant climbed up and over the pyramid as shown by the red line. What is the length of the red path the ant walked? 30 cm, 60 cm, 70 cm, 80 cm, or 90 cm? As we see the ant went up and down the pyramid. The ant also went across the pyramid at the same time. First let's look at the height of the pyramid. We see that the ant went up 3 cubes. The 3 cubes that are 10 cm each totals 30 cm. So the ant has walked 30 cm so far. Then going down is the exact same thing. So that will be another 30 cm. Then we have to add the distance walked across. We see on this other diagram that the structure is only 3 cubes wide. So the ant also walked 30 cm across. So until we have 30 cm plus 30 cm plus 30 cm which equals 90 cm. Which means our answer must be E. 90 cm.

pyramid

cubes

ant path

distance

geometry