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Answer :

There are two circular models, one with radius 7 inches and another is radius 6.5 inches

Since the angles are in degrees, let us convert the angles from degree to radian.

[tex]\begin{gathered} 45^o=\frac{\pi}{4} \\ 40^o=\frac{2\pi}{9} \end{gathered}[/tex]

the length of the curve section with radius 7 inches is

[tex]\begin{gathered} A=\frac{\pi}{4}\times7 \\ =5.497 \end{gathered}[/tex]

the length of the curve section with radius 6.5 inches is

[tex]\begin{gathered} B=\frac{2\pi}{9}\times6.5 \\ =4.538 \end{gathered}[/tex]

So, the total length is

[tex]\begin{gathered} L=5.497+4.538 \\ =10.035 \\ \approx10.0\text{ (rounded off to the nearest tenth)} \end{gathered}[/tex]

Hence, the correct option is (c)