Prove that one of the sides of a Pythagorean triangle is a multiple of 3.
26857
In any Pythagorean triplet at least one of them is divisible by $2$, $3$ and $5$.
109964
the converse of Pythagoras Theorem
84334
How to prove the Pythagoras theorem using vectors
136054
If $a_1,a_2,a_3,...,a_n$ are the side lengths of $A_1A_2A_3...A_n$ convex polygon,then$\frac{a^2_1+a^2_2+a^2_3+....+a^2_{n-1}}{a^2_n}$ is
45702
For any triangle with sides $a$, $b$, $c$, show that $a^2b(a-b)+b^2c(b-c)+c^2a(c-a)\ge 0$
111003
Prove that if $A\triangle B = C\triangle B$, then $A = C$
154716
Prove $\frac{1}{a^3+b^3+abc}+\frac{1}{a^3+c^3+abc}+\frac{1}{b^3+c^3+abc} \leq \frac{1}{abc}$
142835
Proving :$\arctan(1)+\arctan(2)+ \arctan(3)=\pi$
23097
Prove that every number ending in a $3$ has a multiple which consists only of ones.
62126
Constructing a triangle given 2 sides and the inscribed circle's radius
50534
Prove that if $n^2$ is divided by 3, then also $n$ can also be divided by 3.
7966
How prove $ \sqrt{2}+\sqrt{3}>\pi$?
79777
An olympiad Geometry problem involving triangles
137608
Proof of Euclid's formula for primitive Pythagorean Triples
17264
Given $a,b,c$ are the sides of a triangle. Prove that $\frac{a}{b+c}+\frac{b}{c+a}+\frac{c}{a+b}<2$
97473
Prove that: area of triangle $S_{ABC}=p \cdot R$, where p is half perimeter of triangle $DEF$
87206
Prove that a triangle can be inscribed in the hyperbola $xy=c^2$ whose sides touch the parabola $y^2=4ax$.