9514 1404 393
Answer:
49π m² ≈ 154 m²
Step-by-step explanation:
The formula for the area of a circle is usually remembered as ...
A = πr² . . . . . for radius r
Here, we're given the diameter. We can either figure the radius from the diameter and use this formula, or we can rewrite the formula to use the diameter.
r = d/2 = (14 m)/2 = 7 m
A = π(7 m)² = 49π m² . . . . . "exact" answer
Sometimes when multiples of 7 are involved, we like to use π ≈ 22/7. Using that value, the area is ...
A = 49π m² = 49(22/7) m² = 154 m² . . . . . approximation using π = 22/7
Often, algebra problems insist on using the value π = 3.14. For that value, the area is ...
A = 49π m² = 49(3.14) m² = 153.86 m² . . . . . approximation using π = 3.14
Using the "pi button" on your calculator, the numeric answer is ...
A ≈ 49(3.14159265359) m² ≈ 153.938 m² . . . . using "pi button"
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If we rewrite the formula to use the diameter directly, then the area is ...
A = π(d/2)² = (π/4)d²
For the diameter of 14 m, this is ...
A = (π/4)(14 m²) = π(196/4) m² = 49π m² . . . . same as above
