Question

I need a bit of explanation please. No direct answers.
A water sprinkler has a range of 5 meters as shown. The jet of water from the sprinkler sweeps out at an angle of 85° as the nozzle turns. What is the area watered by the sprinkler? Use the value π = 3.14, and round your answer to one decimal place.

Answer 1

A. 15.6 square meters

B. 17.8 square meters

C. 18.5 square meters

D. 19.2 square meters

Answer 2

@iGreen Could you please lend me a hand here?

Answer 3

@Nnesha Would you mind to quickly explain what I have to do to find my answer? Please.

Answer 4

@iambatman @ganeshie8 @TuringTest Please??

Answer 5

whats the area of circle with radius 5 ?

Answer 6

what I have done so far is find the circumference. which my guess is that 5 is the radius

Answer 7

but I have to make it into a 0.5 when I do this. Look, 2pi(0.5)

Answer 8

that equals 3.14

Answer 9

the question is about area, not the circumference

Answer 10

but then when put it into the equation to find the length of the arc it doesn't work out so well. I put 85/360 x 3.14

Answer 11

I don't know about finding that. Maybe in the subject is called something else but I don't really get it.

Answer 12

First find the area of circle of radius : 5

Answer 13

0.741?

Answer 14

I'm looking at my notes and this is what I got.

Answer 15

It says measure of central angle/360 x pi

Answer 16

the measure of the central angle is 85. so I did 85/360 x pi

Answer 17

what formula are you using for area of circle ?

Answer 18

It's called radian measure

Answer 19

look up area of circle formula in ur notes

Answer 20

I don't have that. I was guessing that it would be one of the formulas I had. I wrote everything I went through in the lesson and it wasn't included

Answer 21

okay I found it on google its a=rpi^2

Answer 22

no A=pi(r)^2

Answer 23

i got 0.785

Answer 24

yes
Area = pi*r^2

plugin r = 5, what do you get ?

Answer 25

78.5

Answer 26

for some reason in the lesson, it was required that I made the radius into a decimal. so if the radius was 5 it'll be 0.5

Answer 27

Yes, thats the area of entire region interior to circle

Answer 28

no need for all that

Answer 29

okay

Answer 30

So what is my next step

Answer 31

we want the area corresponding 85 degrees only, so multiply that area of full curcle, 78.5, by the ratio 85/360

Answer 32

oh okay thank you so much!!

Answer 33

18.53

Answer 34

Area watered by the sprinkler is given by
\[\dfrac{85}{360}\times 78.5\]

simplify

Answer 35

Thank you for your help! I appreciate it a lot! huge help :)

Answer 36

`18.5` is correct

they want you round the answer to just one decimal place

Answer 37

yw:)