Answer: The surface area of the triangular prism is 1071 square millimeters.
Explanation:
To find the surface area of a triangular prism, we need to add up the areas of all its faces.
The triangular face has a base of 18 mm and a height of 12 mm, so its area is:
(1/2) * 18 mm * 12 mm = 108 mm^2
There are two of these triangular faces on either end of the prism, so their combined area is:
2 * 108 mm^2 = 216 mm^2
The other three faces are all rectangles, with a length of 19 mm and a height of 15 mm. The area of each rectangle is:
19 mm * 15 mm = 285 mm^2
There are three of these rectangular faces, so their combined area is:
3 * 285 mm^2 = 855 mm^2
To find the total surface area of the triangular prism, we add up the areas of all its faces:
Total surface area = 216 mm^2 + 855 mm^2 = 1071 mm^2
Therefore, the surface area of the triangular prism is 1071 square millimeters.