Find the missing shape in the pattern puzzle.

Let me carefully analyze the pattern in the grid.

The grid has 4 boxes:
- Top-left: a large triangle with an inner smaller triangle (both yellow/orange, outlined)
- Top-right: a small triangle (same style, but just one — no inner shape)
- Bottom-left: a circle split vertically into red (left) and purple (right)
- Bottom-right: ? (empty)

I need to find how the top row relates to the bottom row — maybe it's about size or structure.

Look at the top row:
- Left: large triangle with inner triangle → looks like a “nested” shape
- Right: just a small triangle — maybe the *inner* part only?

Now bottom-left is a circle split into two colors. Maybe the missing box should be the “inner” or simplified version of that.

But wait — perhaps it’s about removing the outer layer.

Top-left: big triangle containing a smaller triangle → if you remove the outer triangle, you get just the inner small triangle → which matches top-right!

So rule: right box = inner part of left box.

Apply same rule to bottom row:
- Bottom-left: a circle divided into two halves (red and purple). What is the “inner part”? It’s not nested like the triangle.

Alternatively, maybe it’s about symmetry or division.

Another idea: look at shapes and their orientations.

Top-left triangle points up; top-right small triangle also points up — same orientation.

Bottom-left circle is split vertically. So maybe the missing shape should be a *half-circle*? But none of the options are half-circles.

Let me list the answer choices:

① full circle, left red / right purple (same as bottom-left)
② small triangle (like top-right)
③ small circle, top red / bottom purple (vertical split rotated?)
④ small circle, left red / right purple (same split, but smaller)
⑤ triangle with inner triangle, but red/purple coloring? Wait — it's a triangle with inner triangle, both red/purple? Actually, it looks like a triangle with a smaller triangle inside, both filled red/purple — but original top-left was yellow/orange.

Wait — let me zoom in on the options to read details clearly.