Answer: 8 pi
Step-by-step explanation: So we know that area of a circle is pi times r^2 so if we reverse that formula it would be square root of 16 pi which would be 4 pi and divide by pi so the radius is 4. And we know that the formula for circumference is 2 times pi times r, so 2 times 4 times pi is 8 pi. 8 pi is the cIrcumference! :)
Answer:
Less
Step-by-step explanation:
Interpreting this, total is 40, so if you are splitting that with multiple people, it can't be more than 40.
Answer:
Both answers will give an area of 2400 ft2
but with x=60 we have lawn dimensions -60 ft by -40 ft so this is out
x = 10 ft width for the sidewalk
Check: New lawn dimensions
(80-2x)(60-2x) = 60(40) = 2400 ft^2
Step-by-step explanation:
Draw a diagram:
We have a rectangle inside a rectangle.
The larger outside rectangle is the original lawn: 80ft by 60 ft with area 4800 ft2
The smaller inside rectangle is (80-2x)by(60-2x) where x is width of the new sidewalk.
Area of new lawn is 2400 ft^2
(80-2x)(60-2x) = 2400
4800 - 160x - 120x + 4x2 = 2400
4x2 - 280x + 2400 = 0
Factor out a 4
x2 - 70x + 600 = 0
(x-60)(x-10) = 0
x = 60 ft or x = 10 ft
The answer is the second one
