The first two are correct. Your last one isn't right.
C = pi * d
The triangle below has a height of 12 feet and a base of 9 feet. What is the area of the triangle?
A.108
B.54
C.21
D.30
B?
If the area of a square is 81 square meters which formula would you use to calculate the perimeter of the square?
A.p=lxw
B.p=s+s
C.p=4(s)
D.Not here
C?
The circumference of this circle is approximately 66 inches. What is the radius?
A.33
B.22
C.11
D.Not here
D?
4 answers
I don't know the diameter.
But you do know the circumference. And you know the value of pi.
Oh. Because I was using the formula radius=C/2 pi