Determine if a triangle is right angled with only coordinates
92916
Show that $(2,0,4) , (4,1,-1) , (6,7,7)$ form a right triangle
26334
point on line to form angle
103172
showing certain vertices form an equilateral triangle
10772
Equilateral triangle inscribed in a ellipse
70400
Extracting angles from a simple picture
40596
Proving a relation between inradius ,circumradius and exradii in a triangle
21875
Find a point on a rotated rectangle with known angle
6062
How to find area of triangle from its medians
90708
Comparing angles and working out the difference
158540
Coordinates vs. Geometries: How can we know two coordinate systems describe the same geometry?
27089
Find the radius of the inscribed circle of a right triangle.
95136
Finding center and radius of circumscribed triangle
75691
How to check if a point is inside a rectangle?
40952
Showing that sum of angles of hyperbolic triangle is strictly less than $\pi$
112896
Construct the triangle with given angle bisectors
57053
Is being a right triangle both necessary and sufficient for the Pythagorean Theorem to hold?
98616
How to draw a triangle programmatically