Find the chiameter of a circle and its circumference if its area 15 (1 626 m (1) 394.24 cm (111) 25 Cu?
Answers
Answer:
Diameter of the circle is 22.4. Circumference of circle is 70.4 cm.
Step-by-step explanation:
The area of a circle is
A=\pi r^2A=πr
2
where, r is radius of the circle.
It is given that area of the circle is 394.24 cm².
Substitute A=394.24 and \pi=\frac{22}{7}π=
7
22
in the above formula.
394.24=(\frac{22}{7})r^2394.24=(
7
22
)r
2
394.24\times \frac{7}{22}=r^2394.24×
22
7
=r
2
125.44=r^2125.44=r
2
Taking square root on both sides.
\sqrt{125.44}=r
125.44
=r
11.2=r11.2=r
Radius of the circle is 11.2 cm.
Diameter=2r=2(11.2)=22.4Diameter=2r=2(11.2)=22.4
Diameter of the circle is 22.4.
Circumference of circle is
C=2\pi rC=2πr
Substitute r=11.2 and \pi=\frac{22}{7}π=
7
22
in the above formula.
C=2(\frac{22}{7})(11.2)C=2(
7
22
)(11.2)
C=70.4C=70.4
Therefore, the circumference of circle is 70.4 cm.
#Learn more
If the area of circle is 75.44 sq cm .then what is the circumference
Answer:
Let C be the circumference, A be the area and r be the radius of the circle.
Thus,
A=πr
2
and C=2πr
and
dt
dC
=0.3
Now,
dt
dA
=2πr
dt
dr
and
dt
dC
=2π
dt
dr
⇒
dt
dr
=
2π
0.3
cm/s
∴
dt
dA
∣
∣
∣
∣
∣
r=5
=2π⋅5⋅
2π
0.3
=1.5sq cm/s
Explanation:
hope it helps