Problem

an engineer is planning a new water pipe installation. the circular pipe has a diameter of d=20\text{ cm}d=20 cmd, equals, 20, space, c, m.

what is the area aaa of the circular cross section of this pipe?

give your answer in terms of pi.

The area of the circular cross section of the pipe is

Step-by-step explanation:

we know that

The area of the circle (cross section of the pipe) is equal to

we have

----> the radius is half the diameter

substitute

it will cost dollar $540

the living room is 3 which means if we divide 325/3 then we get $108

therefore if 1part of the living room cost $108 and 3 costed $325

then total 5part of the room will cost 5*108 which gives $540

54 km / hours

step-by-step explanation:

we need to convert seconds to hours

60 seconds = 1 minutes

60 minutes = 1hour

15 m         60 second   60 minutes

  * *         = 54000 meters/ hour

second     1 minute             1 hour

now we need to convert meters to km

1000 m = 1 km

54000 m       1 km

*   = 54 km / hours

hour               1000m