Plans and elevations are flat 2D "snapshots" of a 3D solid, each taken from a direction perpendicular to what you're looking at:

• Plan view — looking straight down from above; shows width and depth.
• Front elevation — looking directly at the front; shows width and height.
• Side elevation — looking directly at the side; shows depth and height.

This isn't just neatness — it's a geometric requirement that lets the three drawings cross-check each other:

• The plan sits directly above the front elevation, and their widths must match exactly.
• The side elevation sits directly beside the front elevation, and their heights must match exactly.
• The depth shown in the plan must reappear as the width of the side elevation.

A hidden line represents an edge that exists on the solid but is blocked from view by a nearer surface — for example, the edges of a hole drilled through a block, or a lower block's edge obscured by one placed in front of it. These must always be drawn as dashed lines, never solid ones. Simple stacks of cubes with no recesses or overlaps usually don't need any; more complex solids with internal voids or overlapping blocks do.

Drawing the 3D solid again, or an unfolded net of it, instead of a genuine flat 2D projection. A plan view is not a smaller 3D sketch — it must be exactly what a flat shadow would look like if cast straight down, with no depth cues at all.

1. Use the plan view to establish the footprint — which grid squares must contain at least one cube.
2. Use the front and side elevations to work out how tall the stack is allowed to be at each position: a column's height is limited by whichever elevation constrains it most.
3. Mentally re-view your built solid from all three directions and check it reproduces the given plan, front, and side elevations exactly.

Some combinations of views can be satisfied by more than one valid 3D solid — if asked for the minimum or maximum number of cubes, consider every valid internal arrangement, not just the first one you find.

A solid is built from unit cubes. Its plan view is a $2\times3$ rectangle of squares. The front elevation shows a maximum height of 2 units on the left two columns and 1 unit on the right column. Describe the front elevation outline you should draw.

1. The front elevation's width must match the plan's width: 3 units wide.
2. Draw a block 2 units tall across the left two columns.
3. Draw a block 1 unit tall across the remaining (rightmost) column.
4. The resulting outline is a stepped shape, 3 units wide, dropping from height 2 to height 1 after the second column — label it clearly as "Front Elevation."