Showing that the sum of the angles of a hyperbolic triangle are less than $\pi$
40952
Showing that sum of angles of hyperbolic triangle is strictly less than $\pi$
45027
number of primitive Pythagorean triangles whose hypotenuses do not exceed n?
73907
Condition for 3 complex numbers to represent an equilateral triangle
110416
Sums of roots of unity
135543
Proof of Angles going beyond 90 degrees in Trigonometry
14799
How to show that the spherical metric satisfies the triangle inequality?
88605
Proof of the Reverse Triangle Inequality
131080
Geometric representation of the sum of a Geometric Series
116223
Show that the angles satisfy $x+y=z$
131919
Vertices of equilateral triangle inscribed in the unit circle
109180
Deriving Sum of a Geometric Progression
34017
Show that $n^{\pi\left(2n\right)-\pi\left(n\right)}2$
111903
An inequality for sides of a triangle
45775
In a $\triangle ABC,$ Evaluation of minimum value of $\cot^2 A+\cot^2 B+\cot^2 C$
114777
Using Rouché's theorem to bound zeroes of partial sums of $e^z$
150310
A finite sum of reciprocals of complex numbers cannot be confined to a half-plane
88283
Proving the length of angle bisector