Answer:
a. 7 by 21
b. a(-12, 2), b(-12, -5), c(9, -5)
Step-by-step explanation:
AD is 3 times the length of AB. X can be the length of AB. Then 3x would be the length of AD. The perimeter is 56, which would also be 3x + x + 3x + x which is 8x. This gives us 8x = 56, meaning that x is 7, or the length of AB is 7. Because AD is 3 times the length of AB (which is 7), AD = 21. Therefore, the dimensions of the rectangle ABCD is 7 by 21.
Coordinates of A have to be 21 units away from D since AD = 21. It goes in the left direction, meaning that 21 is subtracted from 9 (since this is a horizontal edge involving x coordinates) while the y value remains the same. The result is (-12, 2). For coordinate B, it has to be 7 units away from A downwards since AB = 7. This means that you subtract 7 from 2 (involving only the y coordinates), resulting in (-12, -5). For coordinate C, it has to be 21 units from B since BC = AD = 21. Because C is right compared to B, you have to add 21 to -12 (involving only the x coordinate) resulting in (9, -5).
Answer:
The surface area of the cylinder is 
Step-by-step explanation:
we know that
The surface area of the cylinder is equal to
![SA=2[\pi r^{2} ]+2\pi rh](https://tex.z-dn.net/?f=SA%3D2%5B%5Cpi%20r%5E%7B2%7D%20%5D%2B2%5Cpi%20rh)
In this problem we have
----> see the attached figure
assume
substitute
![SA=2[(3.14)(5)^{2} ]+2(3.14)(5)(12)](https://tex.z-dn.net/?f=SA%3D2%5B%283.14%29%285%29%5E%7B2%7D%20%5D%2B2%283.14%29%285%29%2812%29)
