geometry
Angle sum — AMC & AIME Problems
57 problems
Practice every real AMC 8, AMC 10, AMC 12, and AIME problem that uses Angle sum — a geometry concept — each with a professionally curated solution, many with a video solution too, from LIVE by Po-Shen Loh. Browse all concepts or the full past-contest archive.
LIVE focuses on challenge. As a social enterprise, we also explain standard school concepts one at a time, for free, on our sister site Expii. For this idea: Sum of Angles in a Triangle, Polygon Angles, Sum of Exterior Angles.
All problems are used with official legal permission of the Mathematical Association of America (MAA).
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These problems’ difficulty ratings come from real solve attempts on our platform. Tap a band or a contest to filter the list below, and tap a selected band again to include all difficulties. See the full difficulty guide.
AMC 8
AMC 10
AMC 12
- 1950 AMC 12 Problem 12
- 1952 AMC 12 Problem 21
- 1954 AMC 12 Problem 13
- 1954 AMC 12 Problem 31
- 1954 AMC 12 Problem 37
- 1958 AMC 12 Problem 15
- 1958 AMC 12 Problem 29
- 1960 AMC 12 Problem 27
- 1961 AMC 12 Problem 8
- 1961 AMC 12 Problem 25
- 1961 AMC 12 Problem 27
- 1962 AMC 12 Problem 7
- 1962 AMC 12 Problem 20
- 1962 AMC 12 Problem 31
- 1966 AMC 12 Problem 21
- 1968 AMC 12 Problem 6
- 1968 AMC 12 Problem 20
- 1969 AMC 12 Problem 8
- 1972 AMC 12 Problem 21
- 1973 AMC 12 Problem 16
- 1976 AMC 12 Problem 14
- 1978 AMC 12 Problem 12
- 1980 AMC 12 Problem 4
- 1982 AMC 12 Problem 6
- 1983 AMC 12 Problem 5
- 1984 AMC 12 Problem 15
- 1985 AMC 12 Problem 14
- 1986 AMC 12 Problem 3
- 1988 AMC 12 Problem 6
- 1990 AMC 12 Problem 3
- 1999 AMC 12 Problem 7
- 2002 AMC 12A Problem 4
- 2002 AMC 12B Problem 5
- 2007 AMC 12B Problem 3
- 2007 AMC 12B Problem 7
- 2007 AMC 12B Problem 11
- 2008 AMC 12B Problem 4
- 2017 AMC 12A Problem 11
- 2020 AMC 12B Problem 4
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- Brahmagupta’s Formula
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- Heron’s Formula
- Homothety
- Hyperbola
- Incircle, incenter, and inradius
- Inscribed angle
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- Pick’s Theorem
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- Power scaling of length, area, and volume
- Ptolemy’s Theorem
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- Pythagorean Theorem
- Pythagorean Triple
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- Shoelace formula
- Similarity
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- Tangent line
- Transformation
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