A given perimeter length that is circular encloses the maximum area - which are the (analytic) proofs?
19503
Why does a circle enclose the largest area?
69203
Calculus proof for the area of a circle
152236
What is the optimal path between $2$ fixed points around an invisible obstructing wall?
75694
The Schwarz Reflection Principle for a circle
149544
maximum of monic polynomial on unit circle is 1 implies $p(z)=z^n$
158217
Volume of neighborhood of the curve
137473
Isoperimetric inequality on the sphere via calculus of variations
152442
An annulus in $\mathbb R^2$ is path connected
21745
Proof of Heron's Formula for the area of a triangle
55491
Find the area of largest rectangle that can be inscribed in an ellipse
23203
Euclidean distance proof
52594
Can all circles of radius $1/n$ be packed in a unit disk, excluding the circle of radius $1/1$?
19658
$\max_{t\in[0,T]}|x(t)|^2 \le |x(0)|^2e^{\int_0^T|y|^2\,\mathrm ds}.$ using gronwall's lemma?
70656
Height/Radius ratio for maximum volume cylinder of given surface area
149617
Rectangle inscribed in semicircle, find perimeter and more
39692
The length of an interval covered by an infinite family of open intervals
61262
Is $\cot(z)-\frac1z$ bounded on a given circle?