Answer:
B
Step-by-step explanation:
not sure tho
For the rectangle you add 12 plus 9 to get 21 then multiply by 24 to get 288. then. you multiply 15 times 9 to get 135 then divide by 2 to get 67.5 for the top triangle. you then add 12 and 9 together to get 21 and multiply that by 15 to find the middle rectangle then you get 315. you then add all of the final values together to get 670.5 square units
I know its one of the congruent ones, as one is for sure a 90 degree angle, on top of an 180 degree angle, which by law of supplementary angles makes the other one 90 degrees. Not sure on the postulate, maybe someone else can help with that.
the second one
Step-by-step explanation:
Answer:

Step-by-step explanation:
The complete question in the attached figure
we know that
The surface area of a cube is equal to the area of its 6 squares faces
so
The area of one square face is equal to

where
b is the length side of the square
we have

substitute
---> area of one square face
Find the surface area of three cubes
Multiply the area of one square face by 6 (one cube has 6 faces) and then multiply the result by 3 (3 cubes)
so
![SA=3[6(1)]=18\ ft^2](https://tex.z-dn.net/?f=SA%3D3%5B6%281%29%5D%3D18%5C%20ft%5E2)