geometry roots

[will09]

hi , i am new to this site , just wondering if anyone is available to help with this particular maths question ?
cannot understand how to workout part ( c )
file is attached
thanks

 

[Deleted member 4993]

hi , i am new to this site , just wondering if anyone is available to help with this particular maths question ?
cannot understand how to workout part ( c )
file is attached

thanks

It has been worked out for you.

Exactly where are you stuck?

 

[will09]

It has been worked out for you.

Exactly where are you stuck?

i know it is worked out , that was the mark up sheet
the part i was interested in was part C. the 2nd , 3rd and end line.
i now the first line root 162
where does the 9-1/2[9root2] come from have not done this type of sum before
i have attached the original question sheet
cheers

 

[Prove It]

hi , i am new to this site , just wondering if anyone is available to help with this particular maths question ?
cannot understand how to workout part ( c )
file is attached
thanks

They worked out the white area in part (b), and then realised that this white area is doubled in part (c). Once they have that total white area, subtracting it from the square gives the area of the shaded region in (c).

 

[will09]

They worked out the white area in part (b), and then realised that this white area is doubled in part (c). Once they have that total white area, subtracting it from the square gives the area of the shaded region in (c).

hi there , thanks for the reply , but how do you come up with the area of the isosceles triangle as this is partially smaller than half of the sector
cheers

 

[Deleted member 4993]

hi there , thanks for the reply , but how do you come up with the area of the isosceles triangle as this is partially smaller than half of the sector
cheers

What is the formula for area of a triangle? [ = ½ * ? * ? ]

Now look at the solution again!!