设原三角形ABC,BC为底边,AD为高,作底边B'C',取B'D'=BD,从D'作射线D'E,使〈ED' C=45度,在D'E上载取D'A'=DA/2,找到A'点,连结B'A',C'A',即为原三角形ABC的斜二测图,在三角形A'B'C'上作A'F⊥B'C',垂足F,A'F=√2A'D'/2=√...