Geometry Problems 551 - 560

Problem 551.
Parallel lines, Transversal, Angle Sums.

Problem 552.
Parallel lines, Transversal, Angle Sums.

Problem 553.
Quadrilateral, Angles, Sum.

Problem 554.
Concave Quadrilateral, Angles, Sum.

Problem 555.
Parallel lines, Angle Sums.

Problem 556.
Quadrilateral, Diagonal, Angles, Auxiliary Lines.

Problem 557.
Quadrilateral, Midpoints, Sides, Varignon Parallelogram, Area, Auxiliary Lines.

Problem 558.
Quadrilateral, Trisection, Sides, Wittenbauer Parallelogram, Area, Auxiliary Lines.

Problem 559.
Triangle, Cevian, Incenters, Angle, 90 Degrees.

Problem 560.
Triangle, Cevian, Incenter, Incircle, Perpendicular, Tangent.