Lucas built a composite solid by joining 12 identical blocks, with dimensions 4 inches by 5 inches by 7 inches, into three
ows of four as shown.
7 in.
5 in
4 in
What is the total surface area of the composite solid?
O 521 square inches
1,042 square inches
1,072 square inches
O 1.992 square inches

1042 square inches is the total surface area of composite solid.

Step-by-step explanation:

It is clear from the image that the resulting composite solid is a cuboid.

whose sides are as follows:

Across the length there are 3 blocks along the side of 7 inches each.

Length =

Width = 5 inch

Across the height there are 4 blocks along the side of 4 inches each.

Height =

We know that total surface area of a cuboid is as follows:

Hence, total surface area = 1024 square inches

i found two solutions,   n = 2 • ± √3 = ± 3.4641

step-by-step explanation: