Area of a sector of a circle (shaded portion)

[ElissaHatesMath]

What I have

A= 1/2*(9)^2*(2*pi/3)

A= 27/2*(2*pi)

A=27*pi

In decimal answer it's 84.8

Keeps telling me it's wrong even though I double checked with another source

 

[Deleted member 4993]

What I have

A= 1/2*(9)^2*(2*pi/3)

A= 27/2*(2*pi)

A=27*pi

In decimal answer it's 84.8

Keeps telling me it's wrong even though I double checked with another source

Now you need to subtract the area of the triangle to calculate the "pink" area.

 

[tkhunny]

What I have

A= 1/2*(9)^2*(2*pi/3)

A= 27/2*(2*pi)

A=27*pi

In decimal answer it's 84.8

Keeps telling me it's wrong even though I double checked with another source

If only there were a way to know what the machine wants. Maybe add units? Maybe two decimal places?

 

[pka]

What I have
A= 1/2*(9)^2*(2*pi/3)
A= 27/2*(2*pi)
A=27*pi
In decimal answer it's 84.8
Keeps telling me it's wrong even though I double checked with another source

You are looking for the area of a circular segment.
See formulas (15)-(18).

 

[mmm4444bot]

… In decimal answer it's 84.8 …

The instructions say, "Round your answer to two decimal places." :cool:

 

[ElissaHatesMath]

I did

The instructions say, "Round your answer to two decimal places." :cool:

Still didn't work

 

[mmm4444bot]

Just to be sure, you did the subtraction you were told about in post #2, yes? What's your new value?

r^2/2 * 2*Pi/3 - r^2/2 * sin(2*Pi/3)