Question

i got a question abt surface area (in description!)

Answer 1

if i want to calculate the surface area of a cylinder mug, but there's only one base (the other base is open), do i have to edit the formula so it's (2πrh) + (πr^2) instead of (2πr^2). also how do i do it with a cone? thanks!

Answer 2

Yes, you are correct.

Answer 3

And what do you mean, " how do i do it with a cone"?

Answer 4

i'm measuring something like an ice cream cone. if the cone has no base how do i find the surface area?

Answer 5

do you have height and radius of the cone ?

Answer 6

h=15cm r=5cm

Answer 7

alright first you have to find slant height
amyhashimoto77 is already helping u ( don't want to jumpppp in :=))

Answer 8

so: √5^2+15^2

is it 40?

Answer 9

but anyz lets start
first use Pythagorean theorem to find slant height \[\rm I^2= h^2 +r^2\]

Answer 10

oh sh*t im wrong

√5^2+15^2 = 20?

Answer 11

that looks incorrect .

Answer 12

how did you get 20 ?

Answer 13

lemme find a calculator lol

Answer 14

it's 5√10

Answer 15

ah so u used fancy calculator
yes that's correct
5^2 = 25
15^2= 225
so we get \[\sqrt{25+225} = \sqrt{250}\]
250 isn't a perfect square so we have to find factors of 250
and divide inot two number (one of them should be the perfect square root )
so \[\sqrt{250} \rightarrow \sqrt{25 \times 10} \rightarrow 5\sqrt{10}\]

Answer 16

to find total surface area use the formula \[\rm SA=\pi r^2 +\pi rl\]