New posts in Quadrilateral

In trapezoid $ABCD$, $AB \parallel CD$ , $AB = 4$ cm and $CD = 10$ cm.

Prove that $\frac{AB}{AE} + \frac{AD}{AG} = \frac{AC}{AF}$ in parallelogram $ABCD$, where $E$, $F$, $G$ are points on a line intersecting the sides

$a,b,c,d$ are complex numbers corresponding to points $A,B,C,D$ lying on a circle with origin as center,and chord $AB⟂CD$. Find $ab+cd$

Show this quad is cyclic

In quadrilateral $ABCD$, $\angle BAC=\angle CAD=2\,\angle ACD=40^\circ$ and $\angle ACB=70^\circ$. Find $\angle ADB$.

Ratio of area covered by four equilateral triangles in a rectangle

Find an angle in the given quadrilateral

Extending the Law of Cosines formula to quadrilaterals (and even polygon?)

How to prove that no quadrilateral exist with three equal angles and increasing sidelengths

Area of parallelogram = Area of square. Shear transform