The diameter of a circle and the side length of a square are both equal to 8 cm. Who is the larger of the area of a circle and that of a square fast

The diameter of a circle and the side length of a square are both equal to 8 cm. Who is the larger of the area of a circle and that of a square fast

The circle area is 3.14 × 8 / 2 × 8 / 2 = 50.24 square centimeter
The square area is 8 × 8 = 64 square centimeters
So it's a big square

Use three cuboids 5 cm long, 3 cm wide and 2 cm high to make a cuboid with the smallest surface area. How many square centimeters is the surface area of this cuboid
Write arithmetic
What's the volume

In order to minimize the surface area, it is necessary to reduce the surface area by the most after composition. Therefore, the surfaces of 5x3 are combined to form a cuboid of 5x3x6 (2 * 3)
S = (5 * 3 + 5 * 6 + 3 * 6) * 2 = 126 (cm2)

With three exactly the same cube, put together a cuboid, cuboid surface area is 70 square decimeters, the original surface area of a cube is______ Square decimeter

A: the surface area of a cube is 30 square decimeters, so the answer is: 30