Yes because all sides would be equal to 5 which would give you 5*4 = 20 units.
Length: 12
Width: 4 since 12x4=48 and length is 3 times as long as it is wide.
The volume of the candle initially is:
V=Ab*h
Area of the base of the cylinder: Ab=pi*r^2
pi=3.14
Radius of the base: r=4 cm
Height of the cylinder: h=6 cm
Ab=pi*r^2
Ab=3.14*(4 cm)^2
Ab=3.14*(16 cm^2)
Ab=50.24 cm^2
V=Ab*h
V=(50.24 cm^2)*(6 cm)
V=301.44 cm^3
The candle melts at a constant rate of:
r=(60 cm^3)/(2 hours)=(120 cm^3)/(4 hours)=(180 cm^3)/(6 hours)
r=30 cm^3/hour
The amount of candle melted off after 7 hours is:
A=(30 cm^3/hour)*(7 hours)
A=210 cm^3
The percent of candle that is melted off after 7 hours is:
P=(A/V)*100%
P=[(210 cm^3)/(301.44 cm^3)]*100%
P=(0.696656051)*100%
P=69.66560510%
Rounded to the nearest percent
P=70%
Answer: 70%
<span>In getting the value of R in the formula of the circumference that you give where as the circumference is equals to 15, the derived formula is R=C/2pi and the answer would be that R is equals to 2.39. I hope you are satisfied with my answer and feel free to ask for more if you have more questions and further clarifications </span>