Answer:
- circumference: 12.56 yd
- area: 12.56 yd²
Step-by-step explanation:
The formula for circumference is ...
C = πd
C = (3.14)(4 yd) = 12.56 yd . . . . . . . . fill in the numbers; do the arithmetic
The circumference is 12.56 yd.
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Since the diameter is 4 yd, the radius is half that, or 2 yd. The formula for the area is ...
A = πr²
Fill in the numbers and do the arithmetic.
A = (3.14)(2 yd)² = 12.56 yd²
The area is 12.56 yd².
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<em>Comment on units</em>
In problems such as these, I find it is often useful to keep the units with the numbers. The units can be treated like any variable: multiplied, divided, measures combined by addition or subtraction of "like units".
Just as (2a)² = 2²·a² = 4a², so does (2 yd)² = 2²·yd² = 4 yd². You can be sure that if the units of the problem don't make sense, there is an error somewhere.
Circumference = 2pir
=2×pi×1.6
=10.05
Area= pir^d
=pi × 6.3
=19.79
If he'll have 5 tests and the average is 90, this means that the scores of each test added must be equal to 90 * 5 or 450.
450 = 90 + 82 + 95 + 86 + x
450 = 353 + x
97 = x which means that he must get a 97% on the fifth test to have an average of 90%
Pretty sure its B but if im wrong please dont be mad.
