You have the correct answer checked already. B
9514 1404 393
Answer:
3a by 4a
Step-by-step explanation:
For dimensions L and W, the area and perimeter are ...
A = LW = 12a^2
P = 2(L+W) = 14a
Using the second equation, we can find L:
L +W = 7a . . . . . divide by 2
L = 7a -W
Substituting into the area formula gives the quadratic ...
(7a -W)(W) = 12a^2
W^2 -7aW +12a^2 = 0 . . . . arrange in standard form
(W -3a)(W -4a) = 0 . . . . . . . factor (find factors of 12 that total 7)
Then we have the two solutions ...
W = 3a, L = 4a
W = 4a, L = 3a
The rectangle dimensions are 3a by 4a.
Answer:
10
Step-by-step explanation:
maximum= most walked
then minimum would be least amount walked
Answer:
1222
Step-by-step explanation:
You have a triangular prism on top of a rectangular prism. The surface area is the sum of the areas of the exposed faces.
Starting with the triangular prism, the surface area is the area of the two triangular bases plus the area of the two rectangular sides (the bottom rectangular face is ignored).
A = ½ (10) (12) + ½ (10) (12) + (13) (9) + (13) (9)
A = 60 + 60 + 117 + 117
A = 354
The surface area of the rectangular prism is the area of the two rectangular bases (front and back), plus the two walls (left and right), plus the bottom, plus the top (minus the intersection with the top prism).
A = (19) (11) + (19) (11) + (9) (11) + (9) (11) + (19) (9) + (19) (9) − (10) (9)
A = 209 + 209 + 99 + 99 + 171 + 171 − 90
A = 868
So the total surface area is:
354 + 868
1222
1.9 is the answer. But I could be wrong though.
