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I am given that the radius of the semi-circle is r and the short side of the rectangle is r and the long side 3cm. Both shapes have the same perimetre. Work out the value of r.
Any help i will be vvv thankful!!
The perimeter of the rectangle is 3+3+r+r or simplified is 6+2r
2 pi r is the formula for the circumference of a circle.
These two equations must equal the same thing, therefore 6+2r=2pi r so if you rearrange that you will find the value of r :)
Hope this helps!
Thanks for that CHANTELLE - really healpful!