Any one help me answer these questions?
http://img825.imageshack.us/img825/1091/img01143201303192043.jpg
http://img825.imageshack.us/img825/1091/img01143201303192043.jpg
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Area of a circle = πr2 (pie times radius squared) (sorry I can't write the squared sign using this!)
1) Area of blank = π x 20 squared = 1256. 6mm2 (correct to 1 decimal place)
2) The diameter of the hole is 7mm so it's radium is half of that and it is 3.5mm. A = π x 3.5 squared = 38.5mm2 to 1 decimal place.
3) Area of finished washer = Area of blank - Area of hole = 1256.6-38.5 = 1218.1 mm
1) Area of blank = π x 20 squared = 1256. 6mm2 (correct to 1 decimal place)
2) The diameter of the hole is 7mm so it's radium is half of that and it is 3.5mm. A = π x 3.5 squared = 38.5mm2 to 1 decimal place.
3) Area of finished washer = Area of blank - Area of hole = 1256.6-38.5 = 1218.1 mm