Ellipse problem: why are those two angles equal?
117618
How to geometrically prove the focal property of ellipse?
34868
Determining the angle degree of an arc in ellipse?
143600
Does a semicircle have 2 right angles?
104410
Why do we omit the negative sign when finding basic angle when solving trigonometric equations?
150284
Problem about angle in isosceles triangle
130517
$ABCD$ is a square and $AEB$ is an equilateral triangle. Find $\angle DEC$.
73776
Eccentricity of an ellipse
41550
Find the Area of the ellipse
84161
Gauss law question with regard to this example
80004
Why is $1/i$ equal to $-i$?
61641
Equations of lines tangent to an ellipse
90708
Comparing angles and working out the difference
135543
Proof of Angles going beyond 90 degrees in Trigonometry
37448
Two Circles and Tangents from Their Centers Problem
120451
Why Does Snell's Law use Sine Instead of Angle Values?
131812
Does a sphere projected into 2D space always result in an ellipse?
28582
How to find points of tangency on an ellipse?