Find the volume and surface area of the composite figure shown below if the figure is built with unit cubes.
We can start by breaking down the composite figure into smaller, simpler shapes.
First, let's focus on the rectangular prism at the bottom. It has dimensions of 5 units by 3 units by 1 unit, so its volume is:
5 x 3 x 1 = 15 cubic units
Its surface area can be found by adding up the areas of its six faces. The top and bottom faces are both 5 x 3 = 15 square units, while the four side faces are each 3 x 1 = 3 square units. So the total surface area is:
2(15) + 4(3) = 36 square units
Next, let's consider the triangular prism on top of the rectangular prism. It has a height of 2 units and its base is a right triangle with legs of length 2 and 4 units. So its volume is:
(1/2)x2x4x2 = 8 cubic units
To find its surface area, we need to find the area of each face. The two triangular faces are congruent with area:
(1/2)x2x4 = 4 square units each
And the three rectangular faces have areas of:
2 x 2 = 4 square units
2 x 4 = 8 square units
2 x 2 = 4 square units
So the total surface area of the triangular prism is:
2(4) + 3(4+8) = 36 square units
Finally, we can add the volumes and surface areas of the two shapes to find the total volume and surface area of the composite figure:
Volume: 15 + 8 = 23 cubic units
Surface Area: 36 + 36 = 72 square units