论文部分内容阅读
对于方、长方、梯形、三角和圆形等规则图形的面积可以按式计算,但对形状不规则的图形,如没有求积仪,怎样测算其面积呢?取均质纸(如铜版纸、书写纸等)一张、1/10g天平一架(各地医疗室均有)备用。例如现欲求万分之一地形图中某一区域范围的面积?称10厘米×10厘米(一平方公里)的均质纸重量得A克(取小数后一位);再用同一均质纸放地形图下,沿区域范围的边线复描下图形,用剪刀细心剪下图形,用天平称其重量为B克;则区域范围的面积X=B/A(平方公里)
For the square, rectangular, trapezoidal, triangular and circular and other regular graphics area can be calculated according to the formula, but irregularly shaped graphics, such as without the plotter, how to measure the area? Take homogeneous paper (such as coated paper , Writing paper, etc.) one, 1 / 10g a balance (all medical clinics have) spare. For example, you want one tenth of the area of a topographic map. The average weight of a homogeneous paper weighing 10cm x 10cm (one square kilometer) is A gram (take the last decimal place); then use the same homogeneous paper Place the topography along the edge of the area, repeat the figure below, cut the figure carefully with scissors and weigh it with B on a scale. The area of the area X = B / A (km 2)