The formula for circumference is C= 2(pi)(r)^2. Because diameter is double the radius, and the diameter is 8 ft, the radius is 4 ft. So, plug that into the equation, and you get: C=2(pi)(4)^2. The answer is 32 pi ft. If the question asks for the exact answer, keep the pi as it is, but if it says to round, multiply 32 by pi and round.
Angles:
2 acute angles and 2 obtuse angles
Sides:
2 pairs pf parallel sides
2x+(x-10)=4
3x-10=4
3x=14
x=4.6 repeating
I just had this question choose "d" hope it helps
10x+2y=18
10x-7y=-18
Multiply the second one by -1
-10x+7y=18
Then add the two equations
10x+2y=18
+-10x+7y=18
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9y=36
y=4
Plug that back into one of the equations above and solve for x
10x+2y=18
10x+2(4)=18
10x+8=18
10x=10
x=1
so your answer is x=1 and y=4 or (1,4)
