Answer:
242cm^2
Step-by-step explanation:
The formula for surface area of a rectangular(assuming that's what you have) is Perimeter of the Base(height) + 2(Area of the Base)
Or you could add up all the sides, or use this formula
SA=2(length*width)+2(length*height)+2(height*width)
2×(10×7 + 10×3 + 7×3)
helpful links:
https://www.khanacademy.org/math/ basic-geo/basic-geo-volume-sa/basic-geometry-surface-area/v/surface-area-of-a-box
http://www.math.com/tables/geometry/surfareas.htm
https://www.basic-mathematics.com/surface-area-formula.html
