
Help please
Im looking for help with area of shaded region . rectangle is 35m by 14m. there is semicircle flowerbed at eachend. the shaded area is put down to lawn. (i) i worked out combines area of the 2 flowerbeds to be 154m^ (ii) the answer is 114m it asks 'what is the perimeter of the lawn. i cant work it out!! i tried to minus area of rec. by the flower beds but to no avail ! please help me!

Re: Help please
I'm trying to reconstruct in my mind as best as I can what you mean.
i) For the area of the flowerbed, you can calculate the area of the rectangle, and then combine the two semicircles to make a circle and calculate the area that way. (or find the area of one halfcircle and multiply by 2)
ii) This one is trickier. I'm assuming the semicircles are positioned on the shorter ends of the rectangle. Hence the 'exposed' sides of the rectangle are 35 and 35 = 70. Now all we are left with is to calculate are the 'exposed' sides of each semicircle.
but think about combining the two semicircles again to make a full circle. do you know a formula which gives the perimeter of a circle with diameter 14?

Re: Help please
Yes the flowerbeds are inside the rectangle at the shorter ends. yes the length ways of the rectangle is 35 then the height is 14. eh i dont think so just the regular 2 pi r for radius or maybe pi d (diameter) or what about pi r for perimeter of semi circle? sorry for incompetence

Re: Help please
No need to be sorry; learning mathematics is a lifelong experience that takes years of purposeful practice.
You are correct. Here is the reasoning:
Since diameter is equal to double the radius, we have that the circumference of a circle is: pi * d OR pi * 2r.
Since a half circle has half the circumference of a circle, the circumference of a half circle is : (1/2)(pi)(2r) = pi*r
Adding the sides of the rectangle and the arcs, we get
[ 'exposed' sides of rectangle ] + [ 'exposed' sides of semicircles ]
= [ 35 + 35 ] + [pi*7 + pi*7]
= approximately 114

Re: Help please

Re: Help please