The top two nets represent the triangular prisms that are attached to the bases of a rectangular prism. The composite figure is composed of all three prisms. The shaded areas are faces that are shared between the prisms. What is the total surface area of the composite figure?
78 square units
144 square units
282 square units
342 square units

282 square units

Step-by-step explanation:

I just answered this question

for the friend request.

when a figure, such as triangle (xyz) is reflected over the line y = x to create x'y'z' the x-coordinates and y-coordinates of the original image (pre-image) will be reversed for the image. (e.g., (x, y) > (y, x)) this means that the pre-image position of the x- and y-coordinates switch places which in turn provides a mirror like image of the original xyz.  

i notice that when i draw a line segment from x to x', that the points are parallel from each other -- they are exactly across from each other and do not intersect with any other points.  

yes, think i would see the same characteristic if you drew the line segment connecting y with the reflecting line and then y' with the reflecting line because of the essence of reflections. because it is a mirror image, each point was effected the same way which leads me to conclude that they same would apply to y and y'.