Try it on paper first. A hint, the key idea and the worked solution are here when you need them.
A storage box is a cuboid. One corner is at the origin. Its three edges from that corner run along the positive -axis, the positive -axis and the positive -axis, and they are , and long. The box has eight corners. Count how many corners lie on at least one coordinate plane, including the origin. Then count how many corners lie on an axis, not counting the origin.
The three signs of decide the octant. A point on an axis has two zero coordinates, and a point in a coordinate plane has one. The distance of from the -plane is , from the -plane and from the -plane .
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. The corners. Each coordinate is or the edge length. The corners are , , , , , , and .
Step 2. On a coordinate plane. A corner is on a plane if one of its coordinates is zero. Every corner does this except . So corners lie on a coordinate plane.
Step 3. On an axis. A corner is on an axis if two coordinates are zero. Leaving out the origin, these are , and . So corners.
Check. The corner is the only one with no zero coordinate. It is the only corner inside an octant, the first one.
Answer: corners lie on a coordinate plane and corners lie on an axis.
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