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Area and Length of Complex Shapes: all problems

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

0 / 17 solved

Problem 28.5.1

AMC 8

Point OO is the center of the regular octagon ABCDEFGHABCDEFGH, and XX is the midpoint of the side AB‾\overline{AB}. What fraction of the area of the octagon is shaded?

Problem 28.5.2

AMC 8

In the figure, the outer equilateral triangle has area 16, the inner equilateral triangle has area 1, and the three trapezoids are congruent. What is the area of one of the trapezoids?

Problem 28.5.3

AMC 8

The letter T is formed by placing two 2×42\times 4 inch rectangles next to each other, as shown. What is the perimeter of the T, in inches?

Problem 28.5.4

AMC 8

A unit hexagram is composed of a regular hexagon of side length 1 and its 6 equilateral triangular extensions, as shown in the diagram. What is the ratio of the area of the extensions to the area of the original hexagon?

Problem 28.5.5

AMC 8

The area of polygon ABCDEFABCDEF is 52 with AB=8AB = 8, BC=9BC = 9 and FA=5FA = 5. What is DE+EFDE + EF?

Problem 28.5.6

AMC 8

A decorative window is made up of a rectangle with semicircles on either end. The ratio of ADAD to ABAB is 3:23:2, and ABAB is 30 inches. What is the ratio of the area of the rectangle to the combined areas of the semicircles?

Problem 28.5.7

AMC 8

Triangle ABCABC is an isosceles triangle with AB‾=BC‾\overline{AB} = \overline{BC}. Point DD is the midpoint of both BC‾\overline{BC} and AE‾\overline{AE}, and CE‾\overline{CE} is 11 units long. Triangle ABDABD is congruent to triangle ECDECD. What is the length of BD‾\overline{BD}?

Problem 28.5.8

AMC 8

What is the perimeter of trapezoid ABCDABCD?

Problem 28.5.9

AMC 8

In the given figure hexagon ABCDEFABCDEF is equiangular, ABJIABJI and FEHGFEHG are squares with areas 18 and 32 respectively, △JBK\triangle JBK is equilateral and FE=BCFE = BC. What is the area of △KBC\triangle KBC?

Problem 28.5.10

AMC 8

In the figure, ABCDABCD is a rectangle and EFGHEFGH is a parallelogram. Using the measurements given in the figure, what is the length dd of the segment that is perpendicular to HE‾\overline{HE} and FG‾\overline{FG}?

Problem 28.5.11

AMC 8

Two 4×44\times 4 squares intersect at right angles, bisecting their intersecting sides, as shown. The circle's diameter is the segment between the two points of intersection. What is the area of the shaded region created by removing the circle from the squares?

Problem 28.5.12

AMC 8

A square with side length 2 and a circle share the same center. The total area of the regions that are inside the circle and outside the square is equal to the total area of the regions that are outside the circle and inside the square. What is the radius of the circle?

Problem 28.5.13

AMC 8

An equilateral triangle and a regular hexagon have equal perimeters. If the area of the triangle is 4, what is the area of the hexagon?

Problem 28.5.14

AMC 8

Angle ABCABC of △ABC\triangle ABC is a right angle. The sides of △ABC\triangle ABC are the diameters of semicircles as shown. The area of the semicircle on AB‾\overline{AB} equals 8π8\pi, and the arc of the semicircle on AC‾\overline{AC} has length 8.5π8.5\pi. What is the radius of the semicircle on BC‾\overline{BC}?

Problem 28.5.15(additional)

MATHCOUNTS

In the figure, a kite with two right angles is circumscribed by a circle. The circle is then circumscribed by a square such that the diagonals of the kite are parallel to the sides of the square as shown. The longer sides of the kite each have length xx meters. The sides of the kite divide the square into three regions, shaded dark gray, white and light gray as shown, with each region of area 2. If x2=a+bx^2 = a + \sqrt{b}, what is the value of a+ba + b?

Problem 28.5.16(additional)

AMC 10

A regular hexagon of side length 1 is inscribed in a circle. Each minor arc of the circle determined by a side of the hexagon is reflected over that side. What is the area of the region bounded by these 6 reflected arcs?

Problem 28.5.17(additional)

AMC 10

Three identical square sheets of paper each with side length 6 are stacked on top of each other. The middle sheet is rotated clockwise 30∘30^\circ about its center and the top sheet is rotated clockwise 60∘60^\circ about its center, resulting in the 24-sided polygon shown in the figure below. The area of this polygon can be expressed in the form a−bca - b\sqrt{c}, where aa, bb, and cc are positive integers, and cc is not divisible by the square of any prime. What is a+b+ca + b + c?