Respuesta :
Answer: The increase in the diameter is 6 cm.
Step-by-step explanation:
The circumference of a circle with diameter 'd' is given by :
Circumference=[tex]\pi d[/tex]
Given: The circumference is increased from [tex]12\pi\ cm\ to\ 18\pi\ cm[/tex]
It implies the increase in the circumference=[tex]\pi d_2-\pi d_1=18\pi-12\pi[/tex], where [tex]d_1[/tex] is the previous diameter and [tex]d_2[/tex]
is the new diameter.
[tex]\Rightarrow\pi(d_2-d_1)=\pi(18-12)\\\Rightarrow(d_2-d_1)=6[/tex]
Hence, the increase in the diameter= 6 cm
The diameter of the circle must increase by 6
The circumference of a circle is calculated as:
[tex]C = \pi d[/tex]
Given that:
[tex]C_1 = 12\pi[/tex] --- the initial circumference
[tex]C_2 = 18\pi[/tex] --- the final circumference
So, we have:
[tex]\pi d_1 =12\pi[/tex]
[tex]\pi d_2 =18\pi[/tex]
Where:
[tex]d_2 = d + d_1[/tex]
So, we have:
[tex]\pi d_2 = \pi (d + d_1)[/tex]
[tex]\pi (d + d_1) = 18\pi[/tex]
Subtract [tex]\pi d_1 =12\pi[/tex] from [tex]\pi (d + d_1) = 18\pi[/tex]
[tex]\pi(d + d1 - d1) = 18\pi - 12\pi[/tex]
[tex]\pi(d) = 6\pi[/tex]
Divide both sides by [tex]\pi[/tex]
[tex]d= 6[/tex]
Hence, the diameter must increase by 6
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