1) A bug crawls at a rate of 14π units per hour around a circle with a radius of 3.5 units. How many hours does it take the bug to complete 26 revolutions of the circle? (3) 2004-WU4-10 2) A bike’s front wheel has a 1-foot radius. How many revolutions does the wheel make in a one-mile trip? (2) 2004-WO2-7 3) A wheel has a circumference of 3 meters. The radius can be expressed A as meters, with relatively prime integers A and B. What is the value of B A + B? (3) 2004-WU6-4 4) A circular disk has a radius of two units. A point is marked on the edge of the disk. The disk rotates about its center, causing the point to travel a distance of 90 units. How many rotations did the disk make? Round to the nearest tenth. (2) 2004-WO3-10 5) A greeting card is six inches wide and eight inches tall. Point A is three inches from the fold, as shown. As the card is opened to an angle of 45º, how many inches does point A travel? Express your answer in terms of π. (2) 2004-WU8-7 A Happy Birthday 6) A circular field circumscribes a plot of land that is 200 meters on each side, as shown. How many square meters of the circular region are not inside the square region? (3) 2004-WO4-7 200 m 7) The sum of the areas of the six congruent circles is 150π cm2. What is the area of the rectangle? (3) 2004-WU11-7 8) The students of Glenview Middle School are planning a carnival. One of the contests will be a dart throw. The radius of the entire round dartboard is eight inches. What is the radius of the shaded circle if the area of the non-shaded region is three times the area of the shaded region? (3) 2004WU12-7 9) A carpenter wants to make the largest possible circular tabletop from a 4-foot by 8-foot sheet of plywood. If the tabletop is constructed from the two largest congruent semi-circular pieces that can be cut from the sheet, what is the diameter of the resulting table? (3) 2004-WU16-3 8 feet 10) The radius of circle O is 12, and AB and CD are tangent to the circle at B and D respectively. AB = 16, and CD = 5. What is the sum of OC and OA? (2) 1999-WU3-33 D C O A B 11) Two small circles with radii 2 and 3 are externally tangent. A third circle is circumscribed about the first two as shown. What is the ratio of the area of the smallest circle to the area of the shaded region? (2) 1999-WU4-7 12) Two tangent congruent circles are circumscribed by a larger circle. The diameter of the larger circle is 24. Find the area of the shaded region. Express your answer in terms of π. (2) 1999-WU12-8 13) Square MNOP is tangent to circle O at N and P. What is the area of the shaded region? Round to the nearest whole number. (2) 2000-WU1-6 4 cm 14) In the circle, AP = 2 cm, PO = 3 cm, and m<BPO = 90º. What is the length of BP? (2) 2000-WU12-9 A P O B 15) The circle with center A and right triangle ACB have equal areas. Radius AC = 5. What is the length of BC ? Round to the nearest tenth. (2) 2000-WO4-4 B A C 16) A square is constructed on diameter AC such that the area of the square is equal to the area of the circle. What percent of AC is BC? Round to nearest whole number. (3) 2000-WO8-2 A B C 17) A wheel on a racing bike has a diameter of 28 inches. How many complete revolutions will the wheel make in one mile? 2000-WO3-2 (2) 18) The area of this square is 4π square units. What is the area of the inscribed circle? (3) 2003-WU13-2 19) The circle is inscribed in the larger square. The smaller square is inscribed in the circle. The radius of the circle is 10 cm. What is the area of the region between the two squares? (3) 2003-WU14-4 20) A farmer ties his goat to the corner of a 10-foot by 15-foot rectangular shed in an otherwise empty field. The length of rope from the shed to the goat is 25 feet. Over how many square feet of the field can his goat roam? Express in terms of π. (3) 2003-WU13-2 15’ 25’ 10’ 21) A circle is inscribed in a square. What is the ratio of the area of the square not within the circle to the total area of the square? Leave your answer in terms of π. (3) 2002-WU16-4 22) The concentric circles are drawn as shown with radii 2, 4 and 6 units. What is the ratio of the area of the smallest circle to the area of the shaded region? (2) 2002-WU16-5 23) Points A, B, C and D (not shown) are positioned on a circle such that AB = 7, BC = 24, diameter AC = 25 and CD = 15. What is the length of AD ? (3) 2002-WO9-5 B A C 24) A regular hexagon is inscribed in a circle. If the area of the circle is 36π cm2, what is the perimeter of the hexagon? (2) 1997-WU6-10 25) A regular hexagon in inscribed in a circle. If the perimeter of the hexagon is 42 inches, what is the circumference of the circle? Leave your answer in terms of π. (2) 1997-WU8-7 26) An equilateral triangle is inscribed in a circle. Then, a circle is inscribed in that equilateral triangle, an equilateral triangle is inscribed in the second circle and so forth. If the circumference of the largest circle is 12π inches, what is the circumference of the second inscribed circle? (3) 1997-WU13-6 27) A circle is inscribed in a square. Determine the ratio of the circumference of the inscribed circle to the perimeter of the square. Express your answer in terms of π (3) 1997-WO1-7 28) An equilateral triangle is constructed in the interior of a semicircle as pictured. Point B is equidistant from points A and C. If the diameter of the semicircle is 9 inches, what is the area of the triangle? Round your answer to the nearest tenth. (3) 1997-WO4-9 A C B 29) A 3-inch by 4-inch rectangle is rotated about a corner. What is the maximum number of square inches in the area of the region touched by some point of the rectangle as it makes a full rotation? Express your answer in terms of π. (3) 2001-WU7-3 30) What is the ratio of the area of a square inscribed in a semicircle with radius 10 inches to the area of a square inscribed in a circle with radius 10 inches? (3) 2001-WU7-3 31) A goat is attached to an L-shaped rod with a leash that allows the goat to move a ground distance of 8 meters form the rod on all sides. AB = 10 m, BC = 20 m and AB is perpendicular to BC. The attached end of the leash may move along the entire rod and the goat may roam on all sides of the rod. What is the area of the region of grass that the goat may reach? Express your answer in terms of π. (3) 2001-WO1-7 A B C 32) Circles A and B are externally tangent and have radii 9 inches and 16 inches, respectively. What is the length of the common tangent MN? (3) 2001-WO3-8 B A M N 33) A circle with diameter 2 cm in centered at a vertex of the square and of the equilateral triangle. What is the area of the union of the three figures? Round to the nearest hundredth. (3) 2001-WO6-9 34) AB and CD each measure 12”, the arcs are semicircles, AB is bisected and CD is trisected. What is the difference between the areas of the shaded regions of the two figures? (2) 1996-WU11-5 A B C D 35) The diameter of the large semicircle is 8. Find the area of the shaded region. Leave your answer in terms of π. (2) 1996-WO2-5 36) The area of the circle shown is 8π square inches. The base of the triangle is a diameter of the circle. Find the area of the triangle. (3) 1996-WO6-10 37) The circles below are mutually tangent. The areas of the circles are 16π, 25π, 100π and 225π. What is the perimeter of a quadrilateral that has the centers of the circles as its four vertices? (2) 1993-WU9-3 38) Each wheel of Sally’s new bicycle has a diameter of 60 cm. How many revolutions does a wheel make with Sally pedaling a distance of one kilometer? Use π = 3.14 and round to the nearest revolution. (2) 1993-WU126 39) Pascal’s Pizza Parlor is changing the size of its circular pizza from 12 inches to 16 inches and increasing the number of slices per pizza from 8 to 10 pieces. What is the percent increase in the size of each new slice? Express to the nearest whole percent. (2) 1993-WO3-10 40) Circle O has a radius of 12 cm and m AOB is 60º. Find the area of the shaded region. Round to the nearest tenth. (3) 1993-WO5-7 A O 41) In the diagram, mACB 60º and the length of arc AB equals the length of arc PRQ . C is the center 1 B A of arc AB and arc PRQ . Find the ratio of PC to AC. (3) 1995-WU16-9 B P R C Q 42) If a semicircle is constructed on the side of an equilateral triangle, as pictured, what percent of the area of the semicircle lies outside the triangle? Round to the nearest whole percent. (3) 1995-WO4-9 687295018 11 Circles – Answer Key 22) 1/5 1) 13 hrs 2) 23) 20 840 24) 36 cm 3) 5 25) 14π in 4) 7.2 3 5) in 4 6) 22,832 m2 26) 3π in 27) /4 28) 11.7 7) 600 cm2 29) 25 8) 4” 30) 2:5 9) 5 ft 31) 80π + 416 m2 10) 33 in 32) 24 in 11) 1:3 33) 7.56 cm2 12) 72 34) 3π in2 13) 38 cm2 35) 2π 14) 4 36) 8 15) 31.4 37) 68 16) 89% 38) 531 17) 720 39) 42% 18) 2 u2 40) 13.0 cm2 19) 200 cm2 41) 1:5 20) 550 ft2 42) 12% 21) 4 4 687295018 12 Circles