{"id":"cb_question_bank:c2fe1960-f342-48d1-b55a-a5eb7f983f34","source_id":"cb_question_bank","source_item_id":"c2fe1960-f342-48d1-b55a-a5eb7f983f34","external_id":"fa02652e-89a4-4784-990e-fd5f06d65862","ibn":null,"question_id":"ae041e52","program":"SAT","module":"math","domain_code":"S","domain":"Geometry and Trigonometry","skill_code":"S.C.","skill":"Right triangles and trigonometry","difficulty":"H","score_band":7,"answer_type":"mcq","answer_source":"key","layout_warning":null,"form_id":null,"module_number":null,"position":null,"stem":"A square is inscribed in a circle. The radius of the circle is StartFraction 20 StartRoot 2 EndRoot Over 2 EndFraction inches. What is the side length, in inches, of the square?","stimulus":"","stimulus_html":null,"stem_html":"<p style=\"text-align: left;\">A square is inscribed in a circle. The radius of the circle is <math alttext=\"StartFraction 20 StartRoot 2 EndRoot Over 2 EndFraction\"><mfrac><mrow><mrow><mn>20</mn></mrow><msqrt><mn>2</mn></msqrt></mrow><mn>2</mn></mfrac></math> inches. What is the side length, in inches, of the square?</p>","rationale_html":"<p>Choice A is correct. When a square is inscribed in a circle, a diagonal of the square is a diameter of the circle. It's given that a square is inscribed in a circle and the length of a radius of the circle is <math alttext=\"StartFraction 20 StartRoot 2 EndRoot Over 2 EndFraction\"><mfrac><mrow><mn>20</mn><msqrt><mn>2</mn></msqrt></mrow><mn>2</mn></mfrac></math> inches. Therefore, the length of a diameter of the circle is <math alttext=\"2 left parenthesis StartFraction 20 StartRoot 2 EndRoot Over 2 EndFraction right parenthesis\"><mn>2</mn><mfenced><mfrac><mrow><mn>20</mn><msqrt><mn>2</mn></msqrt></mrow><mn>2</mn></mfrac></mfenced></math> inches, or&nbsp;<math alttext=\"20 StartRoot 2 EndRoot\"><mn>20</mn><msqrt><mn>2</mn></msqrt></math> inches. It follows that the length of a diagonal of the square is <math alttext=\"20 StartRoot 2 EndRoot\"><mn>20</mn><msqrt><mn>2</mn></msqrt></math> inches. A diagonal of a square separates the square into two right triangles in which the legs are the sides of the square and the hypotenuse is a diagonal. Since a square has <math alttext=\"4\"><mn>4</mn>\n</math> congruent sides, each of these two right triangles has congruent legs and a hypotenuse of length <math alttext=\"20 StartRoot 2 EndRoot\"><mn>20</mn><msqrt><mn>2</mn></msqrt></math> inches. Since each of these two right triangles has congruent legs, they are both <math alttext=\"45\"><mn>45</mn>\n</math>-<math alttext=\"45\"><mn>45</mn>\n</math>-<math alttext=\"90\"><mn>90</mn>\n</math> triangles. In a <math alttext=\"45\"><mn>45</mn>\n</math>-<math alttext=\"45\"><mn>45</mn>\n</math>-<math alttext=\"90\"><mn>90</mn>\n</math> triangle, the length of the hypotenuse is <math alttext=\"StartRoot 2 EndRoot\"><msqrt><mn>2</mn></msqrt></math> times the length of a leg. Let <math alttext=\"s\"><mi>s</mi>\n</math> represent the length of a leg of one of these <math alttext=\"45\"><mn>45</mn>\n</math>-<math alttext=\"45\"><mn>45</mn>\n</math>-<math alttext=\"90\"><mn>90</mn>\n</math> triangles. It follows that <math alttext=\"20 StartRoot 2 EndRoot equals StartRoot 2 EndRoot left parenthesis s right parenthesis\"><mn>20</mn><msqrt><mn>2</mn></msqrt><mo>=</mo><msqrt><mn>2</mn></msqrt><mfenced><mi>s</mi></mfenced></math>. Dividing both sides of this equation by <math alttext=\"StartRoot 2 EndRoot\"><msqrt><mn>2</mn></msqrt></math> yields <math alttext=\"20 equals s\"><mn>20</mn><mo>=</mo><mi>s</mi></math>. Therefore, the length of a leg of one of these <math alttext=\"45\"><mn>45</mn>\n</math>-<math alttext=\"45\"><mn>45</mn>\n</math>-<math alttext=\"90\"><mn>90</mn>\n</math> triangles is <math alttext=\"20\"><mn>20</mn>\n</math> inches. Since the legs of these two <math alttext=\"45\"><mn>45</mn>\n</math>-<math alttext=\"45\"><mn>45</mn>\n</math>-<math alttext=\"90\"><mn>90</mn>\n</math> triangles are the sides of the square, it follows that the side length of the square is <math alttext=\"20\"><mn>20</mn>\n</math> inches.</p>\n<p>Choice B is incorrect. This is the length of a radius, in inches, of the circle.</p>\n<p>Choice C is incorrect. This is the length of a diameter, in inches, of the circle.</p>\n<p>Choice D is incorrect and may result from conceptual or calculation errors.</p>","correct_answer":["A"],"has_media":false,"has_mathml":true,"has_table":false,"source_created_at":"2023-08-02T20:25:59.840000+00:00","source_updated_at":"2023-08-02T20:25:59.840000+00:00","options":[{"label":"A","content_html":"<p><math alttext=\"20\"><mn>20</mn>\n</math></p>","ord":0},{"label":"B","content_html":"<p><math alttext=\"StartFraction 20 StartRoot 2 EndRoot Over 2 EndFraction\"><mfrac><mrow><mrow><mn>20</mn></mrow><msqrt><mn>2</mn></msqrt></mrow><mn>2</mn></mfrac></math></p>","ord":1},{"label":"C","content_html":"<p><math alttext=\"20 StartRoot 2 EndRoot\"><mrow><mn>20</mn></mrow><msqrt><mn>2</mn></msqrt></math></p>","ord":2},{"label":"D","content_html":"<p><math alttext=\"40\"><mn>40</mn>\n</math></p>","ord":3}],"attribution":{"source_id":"cb_question_bank","source_name":"College Board digital SAT question bank (community dump)","rights_holder":"College Board","canonical_url":"https://satsuitequestionbank.collegeboard.org/","retrieved_from":"https://raw.githubusercontent.com/mdn522/sat-question-bank/main/data/cb-digital-questions.json","attribution":"SAT practice questions © College Board, from the official SAT Suite Question Bank. Retrieved via the community dump at github.com/mdn522/sat-question-bank.","disclaimer":"SAT® and PSAT/NMSQT® are trademarks registered by the College Board, which is not affiliated with, does not sponsor, and does not endorse this project.","license":"College Board copyright; source repository carries no licence. Local use only.","redistributable":false,"item_count":2017}}