The Four-Step Check

You are given two panels and four candidates for the third. The fastest solvers are not the ones who see the object best — they are the ones who ask the same four questions in the same order, and stop the moment three options are gone.

Step one — name the view and its two dimensions

Look at the empty slot before you look at any option. Say which view is missing, then say what the drawing that fills it has to measure: the top view spans width and depth, the front view width and height, the end view depth and height.

Do not skip this because it feels obvious. The generator picks the withheld view fresh for every item, so there is no pattern to lean on, and naming the two dimensions converts a vague "which of these looks right" into a concrete "which of these is depth across and height up."

Step two — the frame check

Cover the insides and look only at each option's outer boundary. The two given panels fix the proportions the asked view must have, by the dimension transfer you ran in the alignment lesson. An option whose outline is the wrong shape of box is out, whatever it contains.

An option that simply reproduces one of the given panels dies here without a second look — and not because its outline is bound to disagree. It is wrong by construction: the withheld view is only ever chosen to be different from both views you were handed, so an option that redraws a panel already on the screen cannot be the answer. Recognize it and strike it, rather than waiting for a proportion to catch it.

Compare options against one another, never an option against a given panel by length — that is the shared-scale rule from the alignment lesson, and it governs this step.

Step three — the feature census

Now go inside, and work feature by feature rather than option by option. Take one feature the given views prove the object has, decide where the asked view must put it, and sweep the survivors for it. One feature checked across three options is a single pass of the eye; one option checked against every feature is three passes.

Position is what this step is for, and position transfers along the shared dimension. A depth measured in from the near edge of the top panel is the same depth measured in from the near edge of the end panel. An option can carry every feature the object has and still be wrong because it placed one of them at a depth the given views never mention.

Step four — the line-style check

Most items never reach this step, and that is exactly why it goes last: the dashed channel is the slowest part of a drawing to read. When two survivors share an outline and put the same features in the same places, the difference is in the dotted lines. The next topic is entirely about those items.

One item, start to finish

TOP VIEW

FRONT VIEW

?

END VIEW

A

B

C

D

Step one. The end panel is the empty one. The end view shows depth across and height up.

Step two. The top panel gives depth against width, the front panel gives height against width, and width is what they share — so depth against height lands at about 1.9 to 1. The answer is roughly twice as wide as it is tall. A is about 3 to 1, and it is the front panel redrawn: it is measuring width across, not depth. Out. B, C and D are all the same 1.9-to-1 rectangle, so all three survive.

Step three. The top view carries two long edges running across the object, close together, a shade under and a shade over a quarter of the depth in from the near edge. In the end view those two lines must sit the same distances in from the left edge, because the left edge of the end panel is the same near face of the object as the bottom edge of the top panel. C puts them there. D puts the identical pair the same distances in from the right edge — it is C reversed. B keeps one of the two and slides the other almost onto the left edge, at a depth nothing in the top view marks. Both out.

Step four. One option is left, so there is nothing to compare. Read C's dashed lines once against the given panels, confirm they are the two edges you just transferred, and answer.

A

B

C ✓

the true end view

D

The asked view is the end view.

Verify the survivor, not the corpses

When three options are gone, the instinct is to go back and reassure yourself about each of them. Resist it. Re-reading a discarded option can only tell you what you already decided, and it doubles what the item costs you. Give that attention to the survivor instead — one clean pass over the option you are about to pick, against the two panels you were handed.

This is safe because the four options are guaranteed to be four different pictures: the generator throws out any candidate whose drawing reads the same as the answer, or the same as an option it has already admitted. Once each option you discarded failed a named check and the survivor passed the ones that ran, another lap buys you nothing.

The takeaway

Name the view and its two dimensions, check outlines, take the census feature by feature, then read the dotted lines. The order is not a preference — it is cheapest-first, so the expensive comparison only ever runs on what is left. Stop as soon as one option stands, and spend your last look on that option rather than on the three you already killed.