Length of 1D curves using 2D integration with $\delta$
131145
Measuring a curve with Dirac delta function.
88283
Proving the length of angle bisector
124401
How to evaluate $\int_0^{2\pi}\frac{1}{(1+a\cos {\theta})^2}\,d\theta$ without contour integration?
52316
Geodesics and Curves on a Plane
36586
Evaluating $\frac{1}{2\pi}\int_{0}^{2\pi}\frac{1}{1-2t\cos\theta +t^2}d\theta$
58924
Possible values of $\int \frac{dz}{\sqrt{1-z^2}}$ over a closed curve in a region?
37091
The Dido problem with an arclength constraint
33278
$\delta$ differential notation
103487
Integration of the cardinal sine
15625
Computing $\int_0^\infty\mathrm{d} x\frac{x}{e^x+1}$ with contour integration
3201
Landau & Lifshitz's Approach (contour method) on the WKB connection formulas
95943
Dimension analysis of an integral
46445
Equation of a helix parametrized by arc length between two points in space
90295
Taking the second derivative of a parametric curve
91446
Average arc length of a uniformly distributed points
27127
Calculating $\iint (x+y) \, dx \, dy$
106515
Use a rectangular contour to evaluate the integral