有甲、乙、丙三个梯形,它们的高之比是1:2:3,上底之比依次是6:9:4,下底之比依次是12:15:10.已知甲梯形的面积是30平方厘米,那么乙与丙两个梯形的面积之和是多少平方厘米?'@/J9M'x/R,v,O-`-|9o(P
算式:提示-Z6~8r1z6Y6|-b2j'@/J9M'x/R,v,O-`-|9o(P
答:乙与丙两个梯形的面积之和是8_5V8_2y/J-Q*V+q1R9Z3z,x平方厘米。'@/J9M'x/R,v,O-`-|9o(P