If volume of cylinder is 900cm² with height of 20cm then diameter of cylinder is

Hello!

Before finding the diameter, we need to know the formula for the volume of cylinder. The volume of cylinder is found by using this formula: V = πr²h. In this formula, r is the radius and h is the height.

Since we have the height and volume, we need to find the radius, and then we can find the diameter.

900 = πr²(20) (divide both sides by 20)

45 = πr² (divide both sides by π)

45/π = r² (take the square root of both sides)

r ≈ 3.784 | The radius of the cylinder is equal to about 3.784 centimeters.

To find the diameter, we need to multiply the radius by 2 because half a diameter is equal to the radius.

3.784 × 2 = 7.568 centimeters | This can be rounded to about 7.57 centimeters.

Therefore, the diameter of the cylinder is equal to about 7.57 centimeters.

(b) 240

step-by-step explanation:

first, we use the pythagorean formula using the given side lengths to find x. then we use x to find the side lengths. then we add the side lengths to find the perimeter.

pythagorean theorem formula:

a^2 + b^2 = c^2

(x - 20)^2 + (x - 40)^2 = x^2

x^2 - 40x + 400 + x^2 - 80x + 1600 = x^2

x^2 -120x + 2000 = 0

(x - 100)(x - 20) = 0

x - 100 = 0 or x - 20 = 0

x = 100 or x = 20

we see that the solution x = 20 must be discarded because it will give a negative side length and a side length of 0. the only valid solution is x = 100.

perimeter = sum of the lengths of the sides

perimeter = x + x - 20 + x - 40

perimeter = 3x - 60

replace x with 100.

perimeter = 3(100) - 60

perimeter = 300 - 60

perimeter = 240