tailieunhanh - Acing The GRE_07

Tham khảo tài liệu 'acing the gre_07', ngoại ngữ, toefl - ielts - toeic phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | THE GRE QUANTITATIVE SECTION Similar Polygons If two polygons are similar their corresponding angles are equal and the ratio of the corresponding sides is in proportion. Example These two polygons are similar because their angles are equal and the ratio of the corresponding sides is in proportion. Parallelograms A parallelogram is a quadrilateral with two pairs of parallel sides. In this figure AB II CD and BC II AD. A parallelogram has the following characteristics Opposite sides are equal AB CD and BC AD . Opposite angles are equal mZA mZC and mZB mZD . Consecutive angles are supplementary mZA mZB 180 mZB mZC 180 mZC mZD 180 mZD mZA 180 . Diagonals bisect each other. Special Types of Parallelograms There are three types of special parallelograms A rectangle is a parallelogram that has four right angles. 193 THE GRE QUANTITATIVE SECTION A rhombus is a parallelogram that has four equal sides. A square is a paralleloram in which all angles are equal to 90 degrees and all sides are equal to each other. AB BC CD DA mZA mZB mZC mZD Diagonals In all parallelograms diagonals cut each other in two equal halves. In a rectangle diagonals are the same length. In a rhombus diagonals intersect to form 90-degree angles. 194 THE GRE QUANTITATIVE SECTION In a square diagonals have both the same length and intersect at 90-degree angles. D C x AC DB and AC DB Solid Figures Perimeter and Area You will need to know some basic formulas for finding area perimeter and volume on the GRE. It is important that you can recognize the figures by their names and understand when to use which formula. To begin it is necessary to explain five kinds of measurement Perimeter The perimeter of an object is simply the sum of the lengths of all its sides. 7 6 4 Perimeter 6 7 4 10 27 10 .