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Question 34517: Missing Side by the Pythagorean Theorem

On this page
  1. Original question and givens
  2. Definition and scope
  3. Step-by-step derivation
  4. Reverse checks
  5. Result
  6. This question review and source binding

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R0068-34517 · q-20260912-pythagorean-missing-side-0017

Original question and givens

A right triangle has leg lengths 20 and 99. Find the hypotenuse length c.

  • G001 — A right triangle has leg lengths 20 and 99. Find the hypotenuse length c.

Definition and scope

Use the original question domain, assumptions and cited MKO definitions. This item has second-context mathematical and bilingual review, with the model, answer and every arithmetic step independently recomputed from the original parameters; the source question remains a candidate.

Step-by-step derivation

S001 · implies

Before

source roles = [qf-pythagorean-missing-side, [hypotenuse, known, legs, mode]]

After

derived = [BASE-no-required-operation, no-invented-domain]

Conditions: none

Separate source banks:legacy RAW SAFE with unbounded derived BigInts versus BASE Number.isInteger without invented SAFE/million caps.Operations,domains and permissive/exact keys follow THIS bank.Keep ORIGINAL JSON intact.

Step identifiers and dependencies

Rule: R68_BANK_specific_keys_operations_and_numeric_guards · Uses: G001

S002 · implies

Before

source roles = [hypotenuse, 20, 99]

After

derived = [right triangle premise, unknown c>0, c^2=a^2+b^2]

Conditions: none

The ORIGINAL bilingual problem GIVES a right triangle and TWO legs.Derive c ONLY from these givens;the already-filled hypotenuse parameter is NOT an oracle.Apply Pythagoras under the GIVEN right-angle premise,not an unqualified converse.

Step identifiers and dependencies

Rule: Pythagorean_GIVEN_right_triangle_TWO_legs_NOT_filled_hypotenuse · Uses: G001, S001

S003 · calculation

Before

Pythagorean ORIGINAL given first leg squared := mul(20, 20)

After

Pythagorean ORIGINAL given first leg squared = 400

Conditions: none

Calculate exactly from ORIGINAL ordered operands;mul/sub/div have EXPLICITLY TWO operands.Legacy derived BigInts are not recapped at RAW SAFE;check BASE Number type/representation conditions separately.Do not use floating approximations to force an answer.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S002

S004 · calculation

Before

Pythagorean ORIGINAL given second leg squared := mul(99, 99)

After

Pythagorean ORIGINAL given second leg squared = 9801

Conditions: none

Calculate exactly from ORIGINAL ordered operands;mul/sub/div have EXPLICITLY TWO operands.Legacy derived BigInts are not recapped at RAW SAFE;check BASE Number type/representation conditions separately.Do not use floating approximations to force an answer.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S003

S005 · calculation

Before

Pythagorean ORIGINAL sum of given leg squares := sum(400, 9801)

After

Pythagorean ORIGINAL sum of given leg squares = 10201

Conditions: none

Calculate exactly from ORIGINAL ordered operands;mul/sub/div have EXPLICITLY TWO operands.Legacy derived BigInts are not recapped at RAW SAFE;check BASE Number type/representation conditions separately.Do not use floating approximations to force an answer.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S004

S006 · calculation

Before

Pythagorean DERIVED positive root squared for reverse substitution := mul(101, 101)

After

Pythagorean DERIVED positive root squared for reverse substitution = 10201

Conditions: none

Calculate exactly from ORIGINAL ordered operands;mul/sub/div have EXPLICITLY TWO operands.Legacy derived BigInts are not recapped at RAW SAFE;check BASE Number type/representation conditions separately.Do not use floating approximations to force an answer.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S005

S007 · implies

Before

source roles = [hypotenuse, 10201]

After

derived = [101, 10201]

Conditions: none

The unknown side has square radicand;substitute back to verify value² exactly.A POSITIVE length selects the positive principal root,not BOTH±branches.All25 ACTUAL roots are exact integers;do not use Math.sqrt approximations or copy filled answer metadata.

Step identifiers and dependencies

Rule: Pythagorean_POSITIVE_length_selects_principal_exact_root · Uses: G001, S006

Reverse checks

  • S007 · premise_and_result_audit — Reverse-check THIS question’s ORIGINAL givens,domain and step premises.Preserve originals/English/MKOs/ASTs/status;do not reverse a one-way implication or call finite checks independent review or general formal proof.
  • S006 · premise_and_result_audit — Recompute Pythagorean DERIVED positive root squared for reverse substitution with exact rational arithmetic, not rounded decimals.
  • S005 · premise_and_result_audit — Recompute Pythagorean ORIGINAL sum of given leg squares with exact rational arithmetic, not rounded decimals.
  • S004 · premise_and_result_audit — Recompute Pythagorean ORIGINAL given second leg squared with exact rational arithmetic, not rounded decimals.
  • S003 · premise_and_result_audit — Recompute Pythagorean ORIGINAL given first leg squared with exact rational arithmetic, not rounded decimals.
  • S002 · premise_and_result_audit — Reverse-check THIS question’s ORIGINAL givens,domain and step premises.Preserve originals/English/MKOs/ASTs/status;do not reverse a one-way implication or call finite checks independent review or general formal proof.
  • S001 · premise_and_result_audit — Reverse-check THIS question’s ORIGINAL givens,domain and step premises.Preserve originals/English/MKOs/ASTs/status;do not reverse a one-way implication or call finite checks independent review or general formal proof.

Result

101

The full substitutions and premise checks give the original answer; source identity,format and status are unchanged.

This question review and source binding

Review date: 2026-10-26

Original questions, answers, step expressions, numeric ASTs and historical records are retained. Source candidate labels remain historical and are not overwritten as formal proof.

Source hashes and review receipts
  • input commit: 0f7be61e2c22317a4075561dc822c87d881a50db
  • original question SHA-256: 98f7ce9468d6ec9921bf99fbdaa8afb974c92445570639f7bf0b6c866d560680
  • candidate record SHA-256: cb2c65f6ac7367ee1ef34d794750975fd728ea4f27163fa3246cf89298cf1b1a
  • semantic review receipt SHA-256: e7a54104fa02c235f7591329bd6db8d626dd74bf0fae29c557b1f269c85066ed
  • question-first witness SHA-256: 8401a3c2064c1275a6a7ea8f00412fa12286cec7b2db6c305ff9dba3724ae229
  • Lean: NOT_RUN · human review: NOT_PERFORMED
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