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Hello, please help me solve this

What is the area of the top of a jar if the diameter of the jar is 3.00 inches?

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Mona B. | Experienced K-6 Teacher for Math, Reading, Writing, and OrganizationExperienced K-6 Teacher for Math, Readin...
5.0 5.0 (22 lesson ratings) (22)
Start with the formula for the area of a circle: area = (pi)(radius)2
Then remember to divide the diameter in half to get the radius (3.00/2 = 1.50)
Then plug in the numbers:
area = (3.14)(1.50)2
area = (3.14)(2.25)
area = 7.065 square inches
To round it to the nearest hundreth (thank you, Steve!) if you normally do that: 7.07 square inches


7.07 is 7.065 rounded to the nearest hundredth, not tenth.
Ryan Y. | Harvey Mudd/Cornell grad; multi-subject, empathetic tutorHarvey Mudd/Cornell grad; multi-subject,...
5.0 5.0 (427 lesson ratings) (427)
Hi Iris,

If a diameter is given for the top of the jar, then it is shaped like a circle.

The area of a circle is A = πr2, where r is the radius of the circle. The radius is exactly half the diameter, so in this case, it's 1.50 inches.

Substituting for r, you get

A = π(1.50 in)2 = 7.07 in2