Surface area problems - 7th grade math

To find the surface area of a solid, we add the areas of the individual faces of the solid. In this video, we calculate the surface area of a tetrahedron and of a right prism that has a parallelogram as a base.

In the second video, we find how much paint you need to cover this water tank if 1 gallon of paint covers 300 square feet. We need to calculate the surface area of the cylindrical water tank (excluding the bottom) and then figure out how much paint is needed.

In the third video, we find out how much wrapping paper is needed to cover a box. This is almost the entire surface area of the box, but not quite.

See also

Pi and the circumference of a circle

Math Mammoth Geometry 3 — a self-teaching worktext with explanations & exercises (grade 7)

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