Answer:
see explanation
Step-by-step explanation:
A
The circumference (C) of a circle is calculated as
C = πd ( d is the diameter ) , then
C = 3.14 × 8 ≈ 25.12 in
B
The circumference (C) of a circle is calculated as
C = 2πr ( r is the radius )
Here C = 94.2 , then
2πr = 94.2 ( divide both sides by 2π )
r = = 15 cm
Answer:
0.67 cm/s
Step-by-step explanation:
The area of a square is given by :
....(1)
Where
x is the side of a square
Differentiating equation (1) wrt t.
When A = 81cm², the side of the square, x = 9 cm
Put all the values,
So, the length of the side of a square is changing at the rate of 0.67 cm/s.