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Polygons: all problems

Focus mode: every practice problem from the chapter, one after another.

0 / 13 solved

Problem 35.4.1

AMC 10

A wire is cut into two pieces, one of length aa and the other of length bb. The piece of length aa is bent to form an equilateral triangle, and the piece of length bb is bent to form a regular hexagon. The triangle and the hexagon have equal area. What is ab\frac{a}{b}?

Problem 35.4.2

AMC 10

This problem also appears in the book as 29.2.1.

Let ABCDEFABCDEF be an equiangular hexagon. The lines AB,CD,AB, CD, and EFEF determine a triangle with area 1923192\sqrt{3}, and the lines BC,DE,BC, DE, and FAFA determine a triangle with area 3243324\sqrt{3}. The perimeter of hexagon ABCDEFABCDEF can be expressed as m+npm + n\sqrt{p}, where m,n,m, n, and pp are positive integers and pp is not divisible by the square of any prime. What is m+n+pm + n + p?

Equiangular hexagon ABCDEF (every angle 120°) with sides 14.76, 6.48, 14.76, 6.48, 14.76, 6.48; perimeter ?; lines AB, CD, EF make an equilateral triangle of side 27.71; lines BC, DE, FA make an equilateral triangle of side 36

ABCDEF
Perimeter = ? (hidden until the end of the example)
Triangle (AB, CD, EF): side 27.71, area 332.55
Triangle (BC, DE, FA): side 36, area 561.18

Equiangular hexagon ABCDEF (every angle 120°) with sides 14.76, 6.48, 14.76, 6.48, 14.76, 6.48; perimeter ?; lines AB, CD, EF make an equilateral triangle of side 27.71; lines BC, DE, FA make an equilateral triangle of side 36

Problem 35.4.3

AMC 10

Two circles lie outside regular hexagon ABCDEFABCDEF. The first is tangent to AB‾\overline{AB}, and the second is tangent to DE‾\overline{DE}. Both are tangent to lines BCBC and FAFA. What is the ratio of the area of the second circle to that of the first circle?

Click a choice or type its letter (A–E).

Problem 35.4.4

AMC 10/12

The figure below is constructed from 1111 line segments, each of which has length 22. The area of pentagon ABCDEABCDE can be written as m+n\sqrt{m} + \sqrt{n}, where mm and nn are positive integers. What is m+nm + n?

Problem 35.4.5

AMC 10

In regular hexagon ABCDEFABCDEF, points WW, XX, YY, and ZZ are chosen on sides BC‾\overline{BC}, CD‾\overline{CD}, EF‾\overline{EF}, and FA‾\overline{FA} respectively, so lines ABAB, ZWZW, YXYX, and EDED are parallel and equally spaced. What is the ratio of the area of hexagon WCXYFZWCXYFZ to the area of hexagon ABCDEFABCDEF?

Problem 35.4.6

AMC 10

Six regular hexagonal blocks of side length 11 unit are arranged inside a regular hexagonal frame. Each block lies along an inside edge of the frame and is aligned with two other blocks, as shown in the figure below. The distance from any corner of the frame to the nearest vertex of a block is 37\frac{3}{7} unit. What is the area of the region inside the frame not occupied by the blocks?

Problem 35.4.7(additional)

AMC 10

A regular octagon is formed by cutting an isosceles right triangle from each of the corners of a square with sides of length 20002000. What is the length of each side of the octagon?

Problem 35.4.8(additional)

AMC 10

Spot's doghouse has a regular hexagonal base that measures one yard on each side. He is tethered to a vertex with a two-yard rope. What is the area, in square yards, of the region outside of the doghouse that Spot can reach?

Problem 35.4.9(additional)

AMC 10

Equilateral △ABC\triangle ABC has side length 11, and squares ABDEABDE, BCHIBCHI, CAFGCAFG lie outside the triangle. What is the area of hexagon DEFGHIDEFGHI?

Problem 35.4.10(additional)

AMC 12

Andrea inscribed a circle inside a regular pentagon, circumscribed a circle around the pentagon, and calculated the area of the region between the two circles. Bethany did the same with a regular heptagon (7 sides). The areas of the two regions were AA and BB, respectively. Each polygon had a side length of 22. Which of the following is true?

Click a choice or type its letter (A–E).

Problem 35.4.11(additional)

AMC 10/12

Equiangular hexagon ABCDEFABCDEF has side lengths AB=CD=EF=1AB = CD = EF = 1 and BC=DE=FA=rBC = DE = FA = r. The area of △ACE\triangle ACE is 70%70\% of the area of the hexagon. What is the sum of all possible values of rr?

Equiangular hexagon ABCDEF (every angle 120°) with sides 1, 5.83, 1, 5.83, 1, 5.83; perimeter ?; triangle ACE is ?% of the hexagon

ABCDEF15.8315.8315.83
Perimeter = ? (hidden until the end of the example)
[ACE] ÷ [hexagon] = ? (hidden until the end of the example)

Equiangular hexagon ABCDEF (every angle 120°) with sides 1, 5.83, 1, 5.83, 1, 5.83; perimeter ?; triangle ACE is ?% of the hexagon

Problem 35.4.12(additional)

AIME

Let △PQR\triangle PQR be a triangle with ∠P=75∘\angle P = 75^\circ and ∠Q=60∘\angle Q = 60^\circ. A regular hexagon ABCDEFABCDEF with side length 11 is drawn inside △PQR\triangle PQR so that side AB‾\overline{AB} lies on PQ‾\overline{PQ}, side CD‾\overline{CD} lies on QR‾\overline{QR}, and one of the remaining vertices lies on RP‾\overline{RP}. There are positive integers a,b,c,a, b, c, and dd such that the area of △PQR\triangle PQR can be expressed in the form a+bcd\frac{a+b\sqrt{c}}{d}, where aa and dd are relatively prime, and cc is not divisible by the square of any prime. Find a+b+c+da+b+c+d.

Problem 35.4.13(additional)

AIME

Let ABCDEFABCDEF be an equiangular hexagon such that AB=6AB = 6, BC=8BC = 8, CD=10CD = 10, and DE=12DE = 12. Denote by dd the diameter of the largest circle that fits inside the hexagon. Find d2d^2.

Equiangular hexagon ABCDEF (every angle 120°) with sides 6, 8, 10, 12, 2, 16; perimeter ?; largest circle inside has diameter ?

ABCDEF681012216
Perimeter = ? (hidden until the end of the example)
Widths between opposite sides: ? (hidden until the end of the example) · Diameter = ? (hidden until the end of the example)

Equiangular hexagon ABCDEF (every angle 120°) with sides 6, 8, 10, 12, 2, 16; perimeter ?; largest circle inside has diameter ?