Arthur D. answered • 07/29/15

Tutor

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(192)
Forty Year Educator: Classroom, Summer School, Substitute, Tutor

the tape is wound around a small plastic cylinder

first find the area of the roll of tape (including the plastic cylinder)

the diameter is 2.9 inches so the radius is 1.45 inches

A=(pi)r^2

A=(3.14159)(1.45)^2

A=(3.14159)(2.1025)

A=6.60519 sq inches

now minus the area of the plastic cylinder

the diameter of the plastic cylinder is 1.4 inches so the radius is 0.7 inches

A=(3.14259)(0.7)^2

A=(3.14159)(0.49)

A=1.539379 sq inches

A=6.60519-1.53938

A=5.06581 sq inches of tape only

when the tape is half used up, you have 5.06581/2=2.532905 sq inches of tape

now add the area of the plastic cylinder to the area of the tape left over (which is half)

A=2.532905+1.539379

A=4.072284 sq inches

A=(pi)(r^2)

4.072284=(3.14159)(r^2)

r^2=4.072284/3.14159

r^2=1.296249

r=√1.296249

r=1.138529

diameter=2*radius

diameter=2*1.138529

diameter=2.277 which is approximately 2.28 inches

Arthur D.

tutor

You are very welcome, Jason.

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07/30/15

Jason W.

07/30/15