# Geometry Problem 1280

### Elements: Quadrilateral, Perpendicular Diagonals, Isosceles Right Triangles,
45 Degrees, Collinear Points.

In a
quadrilateral ABCD, the diagonals AC and BD are perpendicular at E. AFD
and BGC are isosceles right triangle, as shown in the figure. Prove that
the points E, F, and G are collinear.

See also:
Geometry
problem 1280: Typography
in motion.

See also:

Geometry Problems

1271-1280

Visual Index

Open Problems

All Problems

Quadrilateral

Perpendicular lines

Triangles

Isosceles Triangle

45 degrees

Collinearity

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