The prism has 6 faces. Each pair of opposite faces is congruent.
The front and back faces are rectangles that measure 10 cm by 5 cm. The right and left faces are rectangles that measure 5 cm by 3 cm. The top and bottom faces are rectangles that measure 10 cm by 3 cm.
Now we find the area of each rectangle.
The front and back faces are rectangles that measure 10 cm by 5 cm. Each face: A = 10 cm * 5 cm + 50 cm^2
The right and left faces are rectangles that measure 5 cm by 3 cm. Each face: A = 5 cm * 3 cm = 15 cm^2
The top and bottom faces are rectangles that measure 10 cm by 3 cm. Each face: A = 10 cm * 3 cm = 30 cm^2
There are two faces shaped like each rectangle above, so we multiply each rectangle's area by 2, and we add them together.
total surface area = 2 * 50 cm^2 + 2 * 15 cm^2 + 2 * 30 cm^2
