Realm preview · owner review

Owliver Checkwise’s Geometry Realm

Inspired by Pythagoras (c. 570–495 BCE) · Geometry, proof and checking claims · Grades 3–6 (proposed)

Mascots lead the story. The record does the teaching. No invented quotes. Contested claims labeled. Receipts included.

DRAFT · Content and files still in progress

Case file · preview activity

Does this set of lengths make a triangle?

Explore the triangle inequality by checking all three side lengths. A triangle works only when the sum of the two shorter sides is greater than the longest side.

Clue 1 · source detail

Fictional guide illustration · not evidence

3, 4, and 5 make a triangle.

3 + 4 = 7, which is greater than 5.

Clue 2 · source detail

Fictional guide illustration · not evidence

2, 3, and 7 make a triangle.

2 + 3 = 5, which is less than 7.

Clue 3 · source detail

Fictional guide illustration · not evidence

4, 4, and 8 make a triangle.

4 + 4 = 8; equal lengths fold flat, so this is not a triangle.

Make your own theory

Before you peek, what do you think the clues show?

Write or discuss an explanation in your own words. Then compare it with the sourced case note below. This preview doesn’t save responses.

What a careful answer can say: The triangle inequality supports 3–4–5 and rejects 2–3–7 and 4–4–8. The 3–4–5 triangle is also right-angled, but the Pythagorean theorem must not be generalized to every triangle.

What the evidence cannot settle: This check does not prove a historical attribution to Pythagoras. The historical story of who first proved the theorem needs separate source review.

Open the source receipts

Euclid, Elements, Book I, Proposition 20; arithmetic checked independently.

Open decisions

Owner review gates

• Maths accuracy review required before adding any lesson answer keys.
• Pythagorean theorem examples must show a right triangle with a marked 90-degree corner.
• Draft worksheets and answer keys require a full arithmetic audit before any link.

Nothing is listed for sale. Proposed titles, grades, prices and artwork remain review items where noted.

Fictional characters. The history is real. Every Realm ends with the Receipts. This staged preview is awaiting Susan’s final red-pen review.