# I'm struggling with the following question for long. I tried to apply isoperimetric inequality 4

I'm struggling with the following question for long. I tried to apply isoperimetric inequality $4\pi A\le {L}^{2}$, but my attempt has been unsuccessful. Could anyone give me a hint?

Let $AB$ be a segment of straight line and let $l>$ length of $AB$. Show that the curve $C$ joining $A$ and $B$, with length $l$, and such that together with $AB$ bounds the largest possible area is an arc of a circle passing through $A$ and $B$.
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Pranav Greer
Approximate the curve with a sequence of connected straight line segments. Combine this with the straight line segment AB to form a polygon. Now use the theorem that the polygon with maximum area, given the sides, can be circumscribed by a circle.