help. dont really understand this.

Question

barrelracing · Answer

attachment

photon336 · Answer

Yeah, the clue here is the 3mm Hint you can use that to find the radius of the semi circle, and with that it's area.

barrelracing · Answer

so 3^2+3.14? @Photon336

photon336 · Answer

$$\frac{ (\pi*r^{2}) }{ 2 } = Area~semi~circle $$

mathmale · Answer

True.  But why not find the area of the whole circle, and then divide that by 4?  (Why 4?)

photon336 · Answer

how come 4 and not 2? just asking

mathmale · Answer

"3^2+3.14?"  No addition or subtraction here!

barrelracing · Answer

well i tried what photon gave me and i got 9pi/2 i didnt think it was right so i checked in mathway but thats what it said. but when i multiply and divide i get 14.13

mathmale · Answer

Good question, Photon!  I thought it'd be a bit easier to focus on one quarter slice of pie and the triangle drawn inside it first, to find half the shaded area shown.   This would necessitate multiplying that area by 2.

But sure, if you divide the area of the whole circle by 2, that, too, will work, with a bit less effort than my suggested approach.

barrelracing · Answer

ok so what is step one?

mathmale · Answer

Barrel:  the more of your own work you show, the easier it would be for someone to give you feedback on it.

barrelracing · Answer

ok sorry about that

mathmale · Answer

Let me revise my suggestions:

1) find the area of that semicircle as Photon has indicated.
2) find the area of the half square inside which the semicircle appears.
3) subtract the area of the semicircle from the area of the half square.

barrelracing · Answer

ok