X=Y is a straight slant line evenly divided the first and third quadrant.(certainly if it is not on the second quadrant) the line parralleled it will also acrosses the first, third and fourth quadrant. but it saies nothing about the shape of triangle OAB.
if A and B are two points on the line and triangle OAB indicates the triangle shaped by A, B and center point O, then the answer would be C.
area triangleOAB= 3*6/2作者: uclb5550 时间: 2002-12-16 23:06
sorry, " but it saies nothing about the shape of triangle OAB." this sentence should be moved.作者: vincentsam 时间: 2002-12-16 23:09
alright, i see. the answer should be B. No problem. since that line parralels X=Y, the piont that line acrosses ordinate must in the middle point of 6 and is equal with r since this triangle is isosceles triangle. therefore, if we know t=6, then r must be 3. good! thanks for the remind from you and lisaislisa!作者: sylvia 时间: 2002-12-17 13:28
