Question

Please help me please

Answer 1

The total surface area of the cone to 1 decimal place is 377.0 cm^2

Explanation:

r = 6cm

l = 14 cm

We calculate the area for the base,

since the base is a circle,

we have from area of a circle,

Area of circle = (pi)r^2

So, area of base = B =
`\pi (r^2)`

Since r = 6 cm, we get,

`B = (\pi ) (6)^2\\B=36\pi`

Now, the formula for the curved bit is given as,

Area of Curved Part = C = (pi)(r)(l)

Since we know the values of r and l, putting these, we get,

`C =\pi (6)(14)\\C = 84\pi`

So, the total area is the sum of the area of the base and the area of the curved part,

Total Area = T = B + C

`T = 36\pi +84\pi \\T = (36+84)\pi \\T=120\pi`

For, 1 decimal place, we use the value of pi = 3.14159...

using a calculator,

T = 120pi

T = 376.9911184

To one decimal place, we have,

T = 377.0 cm^2

If we use 3.14 for pi, then we get,

376.8 = T

so, the final answer would depend on the value we settle on for pi

In our case, we stick with the calculator answer