Answer: 135cm
Step-by-step explanation
Volume of a cylinder = πr²h
Volume of a cone. = 1/3πr²h
The two shapes are both solid shapes.
Since the have same volume, we can then equate the two together and solve for the height of the cone.
Now make H the height and R the radius of the cylinder and h the height and r the radius of the cylinder.
Now equating the two
πR²H = 1/3πr²h
Now substitute for the values now
Multiply through by 3
3πR²H = πr²h
But π is common so it could be obliterated from the equation
3R²H = r²h
3 x 12² x 20 = 8² x h
3 x 144 x 20 = 64 x h
60 x 144 = 64h
8640. = 64h
Therefore
h = 8640/64
= 135cm
<h2>Given :</h2>
<h2>Solution :</h2>

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Answer:
X=15
Step-by-step explanation:
A +B + C = 180
2x +4x+ 6x = 180
12x =180
X= 15
The total area is 78 sq. ft.
Since the medal platform has different measurements, we need to individually compute the area of each polygon.
The top polygon is a square. Its sides measure 3 ft.
A₁ = a²
A₁ = 3 ft²
A₁ = 9 ft²
The middle polygon is a rectangle.
Its total width can be derived by adding the widths given and the width of the square above.
w = 3 ft + 3 ft + 3 ft
w = 9 ft
A₂ = width * height
A₂ = 9 ft * 2 ft
A₂ = 18 ft²
The bottom polygon is also a rectangle.
w = 4 ft + 9 ft + 4 ft
w = 17 ft
A₃ = width * height
A₃ = 17 ft * 3 ft
A₃ = 51 ft²
Total Area = A₁ + A₂ + A₃
T.A. = 9 ft² + 18 ft² + 51 ft²
T.A. = 78 ft²