Answer:
Look at the unfolded cylinder down: it's consisted of a rectangle and 2 circles. so to find the surface area of the cylinder we should find the areas of the rectangle and the 2 circles.
1) A of 2 circles = 2(π
) = 2π
2) A of rectangle = base x height (or length x width) = bh
but the if we fold the rectangle? what will happen?
the base will go around the circle, this means that the base is equal to the circle circumference, which is 2πr.
Therefore, A of rectangle = 2πrh
3) Surface area of cylinder = 2π + 2πrh
simplify more and take the common factor 2πr:
= 2πr (r+h)
Incorrect, she should have divided both sides by 8. The answer should be x=7. There is only 1 solution to the equation because x is raised to the first degree. It is not a polynomial equation so there won't be more than 1 answer to the equation.
Answer:
36.87
Step-by-step explanation:
Using tan inverse of 9 over 12
A=xy
If there is 10% increase in x then,
New value of x = x + 10%of x =1.1x
similarly for y
New value of y after increase= 1.1 y
New value of A after increase in x and y = 1 .1x × 1.1 y= 1.21xy
now
increase amount in A= New value of A - old value of A
=1.21xy - xy= 0.21xy
percentage increase in A= (0.21xy÷xy )× 100= 21%
