TAILIEUCHUNG - Master the Gre 2010 - Part 31

Peterson's Master the Gre 2010 - Part book includes 9 full-length practice tests , thorough reviews of every section on the exam, and expert tips and strategies from a test prep pro. GRE (Graduage Record Examination General Test) is a commercially-run standardized test and an admission requirement for many graduate schools in USA and other English-speaking countries. GRE can earn you between 200-800 points. | Chapter 11 Math Review Geometry 283 18. The figure above shows a square that is tangent to one circle at four points and inscribed in another. If the diameter of the large circle is 10 what is the diameter of the smaller circle A 5 3 2 B 5 C 2p D 5 2 E The correct answer is D . The square s diagonal is equal in length to the large circle s diameter which is 10. This diagonal is the hypotenuse of a triangle whose legs are two sides of the square. The triangle is right isosceles with sides in the 10 ratio 1 1 2. The length of each side of the square or 5 2. This length 2 is also the diameter of the small circle. Tangents and Inscribed Circles A circle is tangent to a line or line segment if they intersect at one and only one point called the point of tangency . Here s the key rule to remember about tangents A line that is tangent to a circle is always perpendicular to the line passing through the circle s center at the point of tangency. The next figure shows a circle with center O inscribed in a square. Point P is one of four points of tangency. By definition OP T AB. 284 PART IV Quantitative Reasoning A line that is tangent to a circle is always perpendicular to a line connecting the point of tangency and the circle s center. Also notice the following relationships between the circle in the preceding figure and the square in which it is inscribed r radius Each side of the square is 2r in length. The square s area is 2r 2 or 4r2. The ratio of the square s area to that of the inscribed circle is p The difference between the two areas the total shaded area is 4r2 pr2. The area of each separate smaller shaded area is - 4r2 pr2 . For any regular polygon including squares that inscribes a circle The point of tangency between each line segment and the circle bisects the segment. Connecting each vertex to the circle s center creates an array of congruent angles arcs and triangles. For example the left-hand figure below shows a regular pentagon and the

TỪ KHÓA LIÊN QUAN
TAILIEUCHUNG - Chia sẻ tài liệu không giới hạn
Địa chỉ : 444 Hoang Hoa Tham, Hanoi, Viet Nam
Website : tailieuchung.com
Email : tailieuchung20@gmail.com
Tailieuchung.com là thư viện tài liệu trực tuyến, nơi chia sẽ trao đổi hàng triệu tài liệu như luận văn đồ án, sách, giáo trình, đề thi.
Chúng tôi không chịu trách nhiệm liên quan đến các vấn đề bản quyền nội dung tài liệu được thành viên tự nguyện đăng tải lên, nếu phát hiện thấy tài liệu xấu hoặc tài liệu có bản quyền xin hãy email cho chúng tôi.
Đã phát hiện trình chặn quảng cáo AdBlock
Trang web này phụ thuộc vào doanh thu từ số lần hiển thị quảng cáo để tồn tại. Vui lòng tắt trình chặn quảng cáo của bạn hoặc tạm dừng tính năng chặn quảng cáo cho trang web này.