Area

[true silo]

A circle fits inside a semicircle of diameter 10cm as shown.

Calculate the shaded area.

[unborn narwhal]

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[true silo]

I'm unable to upload the picture for some reason, but this is pretty much it for what I found online, except the diameter is 10cm

Oh, this is it

[fast bloom]

you want the radius of the inscribed circle any idea how youd do that

[true silo]

@fast bloom would it be 5?

[fast bloom]

5s the radius of the big semicircle

[hearty temple]

Diameter of small circle = Radius of the larger semicircle = 12
Radius of the small circle = 6
Area of the small circle = 6^2 x π = 36π

Area of the big semicircle = πr^2/2 = π x 12^2/2 = 144π/2 = 72π

Area of the big semicircle - Area of the small circle = 72π - 36π

I reccomend writing it out so that the powers and divisions are easier to see

[fast bloom]

dont give them the full solution, rather just provide a first hint and let them work the rest themselves

[true silo]

@fast bloom Its ok, This isn't the one I'm suppose to solve, I'm suppose to do the grey one so I can learn from this

[hollow crater]

its basically the area of a semi circle minus a smaller full circle

forsay we use the variables as numbers

[zinc fern]

Mr. Macro

Mr. Macro

Mr. Macro

[hollow crater]

we substitute the numbers into the formulas

and minus the two answers

semi circle - full circle and we should get the area of the pink

keys:

r = radius

π = pi

the radius is the mesurment from the middle to the edge of the circle

@true silo if you need further assistance feel free to ping me

[true silo]

@hollow crater Thanks, can I get help with this as well?

[hallow lava]

@true silo has given 1 rep to @harsh trellis

[fast bloom]

for question 1, let the height be h, make an equation for h using volume of a cylinder

[true silo]

@fast bloom Oh I found it, I found the formula through pir²h, I let 2000 be the volume and divided pir² by it

[fast bloom]

nice

[hollow crater]

yes that is the formula to find the volume of a cylinder

[zinc fern]

Mr. Macro

[hollow crater]

h is the hight of the cylinder

to find missing variables rearrangement of the formula can be done

[true silo]

@hollow crater can you say how?

@hollow crater oh, I wanted help with number 2