Extracted text: A uniform concrete slab is to be attached to two rods whose lowers ends are initially at the same level. What is the required area, in mm², of aluminum rod so that slab will remain level after it is attached to the rods? 4 m Aluminum E = 72 GPa Steel A= 96 mm < e="200" gpa="" 4="" m="" 3="" m-="" 0.50="">