Answer:
1 : 1
Step-by-step explanation:
When a circle is inscribed in a cylinder, the height of the cylinder is equal to the diameter of the sphere and the radius of the cylinder is same as that of the sphere.
Let the radius of sphere is r.
height of cylinder, h = 2r
radius of cylinder = r
Surface area of sphere, A = 4πr²
lateral surface area of cylinder, A' = 2 πrh
A' = 2πr x 2r = 4πr²
The ratio of surface area of sphere to the lateral surface area of cylinder is 1 : 1.
Answer:
10.82
Step-by-step explanation:
The surface area of a cylindrical can is equal to the sum of the area of two circles and the body of the cylinder: 2πr2 + 2πrh. volume is equal to π<span>r2h.
V = </span>π<span>r2h = 128 pi
r2h = 128
h = 128/r2
A = </span><span>2πr2 + 2πrh
</span>A = 2πr2 + 2πr*(<span>128/r2)
</span>A = 2πr2 + 256 <span>π / r
</span><span>
the optimum dimensions is determined by taking the first derivative and equating to zero.
dA = 4 </span>πr - 256 <span>π /r2 = 0
r = 4 cm
h = 8 cm
</span><span>
</span>
The base is a square, so the area of the square is (10 cm)² = 100 cm²
To find the area of each triangle use the formula
base • height
10 cm • 9 cm = 90 cm²
now multiply by the number of triangles
90 cm • 4 = 360 cm²
Add the area of the square:
100 cm² + 360 cm² = 460 cm²
I hope it's correct
1236inch (5191.2cm)
primeter of a triangle = sum of its threee sides
P.S. 1 inch=4.2 cm
