Answer:
16.9 m
Step-by-step explanation:
Start with a half a circle. The central angle of a semicircle is 180 deg.
Now subtract 21 deg on each side.
180 - 21 - 21 = 138
The central angle is 138 deg.
The radius is 7 m.
Now we use the formula for the length of an arc of a circle given the radius of the circle and the central angle of the arc.
[tex] s = \dfrac{n}{360^\circ}2 \pi r [/tex]
[tex] s = \dfrac{138^\circ}{360^\circ}2(3.14159)(7~m) [/tex]
[tex] s = 16.9~m [/tex]
