学英语奥数 平面图形.doc

PAGE PAGE 14 平面图形 Look at the figure on right,we know the length of the four lines,and two angles is ninety degrees.Can you work out the area of the quadrangle ABCD? Look at the figure on right,the length of BD,DE and EC is 2,4 and 2,F is the middle point of line AE,the triangle ABC is 4 high,please calculate the area of triangle DEF. In the following diagram, we know the length of the three lines, M is the middle Point of line DE, please calculate the area of quarangle ABMD(the shaded part ). As is shown in the diagram,each side of the exact square(正方形) equals 1. please calculate the area of the shaded part(阴影部分)？ Look at the shadow of the following two parts A and B area.Can you figure out which part is bigger?(the length of sides in rectanglar a are 3,4;and in rectangular B are 2,6 ) The length of exact square’s side equals 1.Please calculate the area of the shaded part.  The length of the sides in the following grass which is a rectangle are 16,10.And there is two roads in the middle, one is a rectangle one is a parallelogram,then what is the area of the shaded part? Seeking the following graphic area. In the following diagram,large square area is 10cm2 larger than the small square area.Please calculate the area of the circle. Find out which of the following area of two triangles are equal? There is a litter square water pool.It is 5 meters long each side.There is grass around the pool everywhere.There is a goat tied to point A,the rope is 6 meters long.How many square meters of grass can the goat get at most? 专题五： 立体图形 一、长方体和正方体面积及体积计算： 二、典型例题 例1：2.1 square meters=( ) square decimeters;2.14 cubic merters=( )cubic decimeters 0.05 cubic merters=( )liters=( ) milliliters. 中文意思：___________________________________________________________________ _____________________________________________________________________________ 答案：_______，_______，________，_______。 例2：Please try to figure out the number of surfaces,and the number of