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UKMT Senior Mathematical Challenge, 2024

Algebra Difficulty 2.0 Junior Find the answer United Kingdom

The sizes of the three angles in a triangle, in degrees, are $x$ , $7x$ and $x^2$ . What is the size of the largest angle?

(A) $10°$ (B) $18°$ (C) $100°$ (D) $120°$ (E) $121°$

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