With all of question 1!
explain also.

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Start with Surface Area formula = LW + 2(pi)(r)^2. Let's look at the top part of the cylinder where you see the given information is 15 cm as your diameter. We know by definition the diameter can be expressed as 2 times radius. We can find radius by setting up the equation 2r = 15 cm we can do inverse operation and divide the 2 to both sides of the equation to get radius (15/2) which equals 7.5. Now knowing radius, we can find area of the circle for the top part by applying Area of a circle = pi times r squared which would be pi times 7.5 times 7.5 which equals 56.25 times 2 since there is a bottom circle we double it. 112.5 pi. Then find the rectangular part of the area by using the the surface area length times width. We know that the Length is equal to the circumference of a circle. Length is 2*pi*r and width is the height so we have 2(pi)(r)(h) = LW. From the formula at start LW + 2(pi)(r)^2 can be written as 2(pi)(r)(h) + 2(pi)(r)^2 = 2(pi)(7.5)(10) + 2(pi)(7.5)^2 =150pi +112.5pi = 262.5pi or 824.67 cm. The other problems can be done similarly.

Step-by-step explanation:

i couldnt understand how the problem was put together, so i found the square root of 13.7 and then did the addition problem that fallowed.

to check to see if a square root answer is correct, just take the answer and put it to the power of 2 and if you return to the original number, the answer is correct

this was done using windows default calculator in scientific mode on a windows 10 device