Isosceles triangle — AMC & AIME Problems | LIVE by Po-Shen Loh

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Isosceles triangle — AMC & AIME Problems

Practice every real AMC 8, AMC 10, AMC 12, and AIME problem that uses Isosceles triangle — 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.

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.

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AMC 8

1988 AMC 8 Problem 9 • 2000 AMC 8 Problem 24 • 2005 AMC 8 Problem 9 • 2006 AMC 8 Problem 19 • 2007 AMC 8 Problem 14 • 2009 AMC 8 Problem 19 • 2011 AMC 8 Problem 16 • 2014 AMC 8 Problem 9 • 2014 AMC 8 Problem 15 • 2015 AMC 8 Problem 6

AMC 10

2002 AMC 10A Problem 23 • 2005 AMC 10B Problem 10 • 2006 AMC 10A Problem 16 • 2007 AMC 10A Problem 8 • 2007 AMC 10B Problem 4 • 2008 AMC 10B Problem 24 • 2009 AMC 10B Problem 9 • 2010 AMC 10B Problem 6 • 2011 AMC 10B Problem 18 • 2014 AMC 10A Problem 22 • 2017 AMC 10B Problem 8 • 2019 AMC 10A Problem 13 • 2019 AMC 10B Problem 16 • 2021 AMC 10A Fall Problem 7 • 2022 AMC 10A Problem 13 • 2023 AMC 10B Problem 7 • 2025 AMC 10A Problem 3 • 2025 AMC 10B Problem 5

AMC 12

1953 AMC 12 Problem 37 • 1954 AMC 12 Problem 31 • 1956 AMC 12 Problem 50 • 1957 AMC 12 Problem 1 • 1957 AMC 12 Problem 44 • 1958 AMC 12 Problem 31 • 1959 AMC 12 Problem 15 • 1959 AMC 12 Problem 26 • 1960 AMC 12 Problem 13 • 1960 AMC 12 Problem 38 • 1961 AMC 12 Problem 25 • 1963 AMC 12 Problem 22 • 1969 AMC 12 Problem 30 • 1970 AMC 12 Problem 30 • 1975 AMC 12 Problem 24 • 1976 AMC 12 Problem 16 • 1977 AMC 12 Problem 4 • 1978 AMC 12 Problem 12 • 1979 AMC 12 Problem 3 • 1979 AMC 12 Problem 12 • 1981 AMC 12 Problem 5 • 1993 AMC 12 Problem 2 • 1999 AMC 12 Problem 19 • 2001 AMC 12 Problem 24 • 2004 AMC 12B Problem 24 • 2005 AMC 12B Problem 6 • 2007 AMC 12A Problem 6 • 2008 AMC 12A Problem 22 • 2011 AMC 12A Problem 13 • 2011 AMC 12B Problem 10 • 2013 AMC 12A Problem 9 • 2013 AMC 12B Problem 16 • 2015 AMC 12A Problem 20 • 2015 AMC 12B Problem 13 • 2021 AMC 12A Fall Problem 6 • 2021 AMC 12B Fall Problem 8 • 2021 AMC 12B Fall Problem 10

AIME

1995 AIME Problem 9 • 2000 AIME I Problem 14 • 2001 AIME I Problem 4 • 2001 AIME II Problem 13 • 2003 AIME I Problem 10 • 2010 AIME II Problem 12 • 2011 AIME I Problem 4 • 2015 AIME I Problem 11 • 2018 AIME I Problem 4 • 2020 AIME I Problem 1 • 2022 AIME I Problem 3 • 2025 AIME II Problem 5

More geometry concepts

3D geometry altitude angle bisector angle bisector theorem angle chasing angle sum annulus arc area area decomposition area ratio Brahmagupta’s Formula British Flag Theorem centroid Ceva’s Theorem chord circle circle area circumcircle, circumcenter, and circumradius circumference cone congruence (geometry)coordinate geometry cube geometry cyclic quadrilateral cylinder diagonal distance formula ellipse equiangular polygon equilateral triangle Euler’s Polyhedron Formula Heron’s Formula homothety hyperbola incircle, incenter, and inradius inscribed angle kite lattice point law of cosines law of sines mass points median (geometry)midpoint net (3D geometry)paper folding parabola parallel lines parallelogram perimeter perpendicular bisector Pick’s Theorem polyhedron power of a point power scaling of length, area, and volume Ptolemy’s Theorem pyramid Pythagorean Theorem Pythagorean Triple radical axis rectangle rectangular prism reflection (geometry)regular polygon rhombus right triangle sector shoelace formula similarity special right triangle sphere square (geometry)Stewart’s Theorem surface area tangent circles tangent line transformation trapezoid triangle area triangle inequality trigonometric identity trigonometry vector Viviani’s Theorem volume