Proving that point of intersection of diagonals of trapezium lies on the line passing through the midpoint of parallel sides?
64504
Prove that the point of intersection of the diagonals of the trapezium lies on the line passing through the mid-points of the parallel sides
72157
Elementary proof of tangent half angle formula
717
Proof of Frullani's theorem
35236
Proof $p \vdash q \Rightarrow p$
114786
Question about Infimum. (conclusion about intersection)
15865
Show that $X = \{ (x,y) \in\mathbb{R}^2\mid x \in \mathbb{Q}\text{ or }y \in \mathbb{Q}\}$ is path connected.
131881
Show that the roots of P' lie in the same half plane as the roots of P
63465
Orthogonal Projection of $ z $ onto the Affine set $ \left\{ x \mid A x = b \right\} $
141101
Russia (2000) contest:Prove the existence of a pair of rows and columns with intersections differently coloured
152921
Proving that Unit Intersection is NP-complete
67313
Proving $\{(x_1, x_2) \in \mathbb{R}^2_{+} \mid x_1 x_2 \geq 1\}$ is convex
90970
How to prove the line exist?
58101
The set of points where two maps agree is closed?
143334
Find a vector parallel to the line of intersection of the two given planes.
130436
bisectors of an angle in a triangle intersect at a single point - proof verification
26919
Intersection of Connected Sets
112866
Is the matrix filled with the areas of pairwise intersections of disks in a plane always positive semidefinite?