Geometry set
20 problems, difficulty 2–4, one per topic where possible
- 1.2006 AMC 10B #5
A rectangle and a rectangle are contained within a square without overlapping at any point, and the sides of the square are parallel to the sides of the two given rectangles. What is the smallest possible area of the square?
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- 2.2011 AMC 10B #9
The area of is one third of the area of . Segment is perpendicular to segment . What is ?

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- 3.2011 AMC 10B #7
The sum of two angles of a triangle is of a right angle, and one of these two angles is larger than the other. What is the degree measure of the largest angle in the triangle?
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- 4.2015 AMC 10B #12
For how many integers is the point inside or on the circle of radius centered at ?
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- 5.2016 AMC 10A #16
A triangle with vertices , , and is reflected about the -axis, then the image is rotated counterclockwise about the origin by to produce . Which of the following transformations will return to ?
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counterclockwise rotation about the origin by .
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clockwise rotation about the origin by .
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reflection about the -axis
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reflection about the line $y = x
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reflection about the -axis.
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- 6.2025 AMC 10A #3
How many isosceles triangles are there with positive area whose side lengths are all positive integers and whose longest side has length ?
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- 7.2010 AMC 10A #16
Nondegenerate has integer side lengths, is an angle bisector, , and . What is the smallest possible value of the perimeter?
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- 8.2011 AMC 10B #17
In the given circle, the diameter is parallel to , and is parallel to . The angles and are in the ratio . What is the degree measure of angle ?

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- 9.2012 AMC 10B #19
In rectangle , , , and is the midpoint of . Segment is extended 2 units beyond to point , and is the intersection of and . What is the area of ?
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- 10.2013 AMC 10B #16
In triangle , medians and intersect at , , , and . What is the area of ?
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- 11.2014 AMC 10A #13
Equilateral has side length , and squares , , lie outside the triangle. What is the area of hexagon ?

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- 12.2018 AMC 10A #16
Right triangle has leg lengths and . Including and , how many line segments with integer length can be drawn from vertex to a point on hypotenuse ?
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- 13.2010 AMC 10A #20
A fly trapped inside a cubical box with side length meter decides to relieve its boredom by visiting each corner of the box. It will begin and end in the same corner and visit each of the other corners exactly once. To get from a corner to any other corner, it will either fly or crawl in a straight line. What is the maximum possible length, in meters, of its path?
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- 14.2011 AMC 10B #25
Let be a triangle with sides and . For , if and and are the points of tangency of the incircle of to the sides and respectively, then is a triangle with side lengths and if it exists. What is the perimeter of the last triangle in the sequence ?
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- 15.2015 AMC 10A #21
Tetrahedron has , , , , , and . What is the volume of the tetrahedron?
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- 16.2017 AMC 10A #21
A square with side length is inscribed in a right triangle with sides of length , , and so that one vertex of the square coincides with the right-angle vertex of the triangle. A square with side length is inscribed in another right triangle with sides of length , , and so that one side of the square lies on the hypotenuse of the triangle. What is ?
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- 17.2018 AMC 10A #21
Which of the following describes the set of values of for which the curves and in the real -plane intersect at exactly points?
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- 18.2019 AMC 10A #21
A sphere with center has radius 6. A triangle with sides of length , , and is situated in space so that each of its sides are tangent to the sphere. What is the distance between and the plane determined by the triangle?
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- 19.2020 AMC 10A #23
Let be the triangle in the coordinate plane with vertices and Consider the following five isometries (rigid transformations) of the plane: rotations of and counterclockwise around the origin, reflection across the -axis, and reflection across the -axis. How many of the sequences of three of these transformations (not necessarily distinct) will return to its original position? (For example, a rotation, followed by a reflection across the -axis, followed by a reflection across the -axis will return to its original position, but a rotation, followed by a reflection across the -axis, followed by another reflection across the -axis will not return to its original position.)
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- 20.2021 AMC 10A #21
Let be an equiangular hexagon. The lines and determine a triangle with area , and the lines and determine a triangle with area . The perimeter of hexagon can be expressed as , where and are positive integers and is not divisible by the square of any prime. What is ?
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