在GRE数学几何中,长方体的是考查的一个重点。下面,小编就带大家去看看GRE数学知识点之长方体实例解析,帮助大家巩固这个知识点。
GRE数学知识点之长方体介绍
rectangular solid (长方体)
A rectangular solid is a three-dimensional (三维) figure formed by six rectangular surfaces,as shown on the right side. Each rectangular surface is a face (面). Each solid or dotted line segment is an edge(边), and each point at which the edges meet is a vertex(顶点). A rectangular solid has six faces,twelve edges,and eight vertices. Opposite faces are parallel rectangles that have the same dimensions.
The volume (V) of any rectangular solid is the product of its three dimensions: length, width, and height.
Volume=length(长)X width(宽)X height(高)=l X w X h
Surface Area=2lh+2lw+2hw=2 (Ih + lw + hw)
GRE数学知识点之长方体实例解析
1. If the areas of three of the faces of a rectangular solid are 6, 10 and 15, what is the volume of the solid ?
(A) 30
(B) 90
(C) 150
(D) 300
(E) 450
题干的意思是:若一个长方体3个面的面积为6,10和15,该 长方体(rectangular solid)的体积是多少?
解:本题的正确答案是(A)。设长方体的长, 宽,高分别为l,w,h,则有:
lw=6
wh=10
hl=15
长方体体积为Iwh,上面三项相乘得lwh = 30。
2. The dimensions, in centimeters, of rectangular box R are 6 by 8 by 10. Which of the following CANNOT be the total surface area, in square centimeters, of two faces of _R?
(A) 96
(B) 120
(C) 128
(D) 160
(E) 180
题干的意思是:以厘米为单位,长方体盒子尺的尺寸为6X 8X10,请问下列哪项不能是只的两个面的面积的和(以平方厘米为单位)?
解:本题的正确答案为(E)。长方体盒子有六面,且对面两两相等,共有三个面积不同的 面,分别是 6X8 = 48,6X 10 = 60 和 8X 10 ==80,这些面两两相加,包括与自身相加, 共有6个不同的取值:分别是:96,120, 160,108,128,140。把这些值与题目的选 项对照,发现(E)不等于长方体盒子两个面的面积的和。考生也可用另一种方法来 解此题,在长方体中面积最大的一面为8 X10 = 80,所以两个最大面的面积和最大为160,因此180显然不能是长方体两个面的面积的和。
3. The rectangular box shown below has been wrapped with two tapes,each going once around the box without overlap and running parallel to the edges of the box. How many centimeters of tape were used on the box?

(A) 70 (B) 80 (C) 120 (D) 140 (E) 150
题干的意思是:下图所示长方体盒子被两条胶带捆住,每条 胶带无重叠地缠绕长方体盒子一圈,且与长方体盒子的边缘相平行。问包盒子共用了多长的胶带?
解:本题的正确答案为(E)。该题实际上是让考生求长方体盒子的两个矩形周长的和,因此 带长等于:2X (20 + 15)+2 X (25 + 15) = 150 cm
以上就是GRE数学知识点之长方体实例解析,希望对大家复习有帮助。
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