Sometimes, Always, or Never (Geometry)
Never
A kite is a square.
Never
A parallelogram contains exactly two right angles.
Never
A parallelogram has both pairs of opposite angles supplementary.
Sometimes
A quadrilateral with diagonals that are perpendicular bisectors of each other is a square.
Sometimes
A rhombus is a square.
Always
A square is a rectangle.
Never
A trapezoid is a parallelogram.
Sometimes
Adjacent angles are complementary.
Never
An acute triangle is a right triangle.
Sometimes
An acute triangle is isosceles.
Always
An equiangular rhombus is a square.
Sometimes
An equilateral parallelogram is equiangular.
Sometimes
An equilateral quadrilateral is a square.
Sometimes
Any three points lie in exactly one plane.
Always
As the number of sides of a regular polygon increases, the measure of each exterior angle decreases.
Sometimes
Each diagonal of a parallelogram bisects two angles of the parallelogram.
Always
If a parallelogram has one right angle, then it is a rectangle.
Sometimes
If a quadrilateral has three angles of equal measure, then the fourth angle must be a right angle.
Always
If points C, D, and E are not collinear, then point C and line AB define a unique plane.
Always
If two angles of one triangle are congruent to two angles of another triangle, then the third pair of angles is congruent.
Sometimes
If two lines are cut by a transversal, then corresponding or alternate interior angles are congruent.
Sometimes
If two sides of one triangle are proportional to two sides of another triangle, the triangles are similar.
Always
Lines in two planes parallel to the same plane are parallel to each other.
Sometimes
Opposite sides of a trapezoid are parallel.
Always
Perpendicular lines form right angles.
Sometimes
The angles of a parallelogram are congruent.
Always
The consecutive angles of a parallelogram are supplementary.
Never
The diagonals of a kite are the perpendicular bisectors of each other.
Sometimes
The diagonals of a quadrilateral are perpendicular and the quadrilateral is not a rhombus.
Sometimes
The diagonals of a quadrilateral bisect each other.
Sometimes
The diagonals of a rectangle are the bisectors of the angles.
Always
The diagonals of a rectangle bisect each other.
Sometimes
The diagonals of a rhombus are equal.
Always
The diagonals of a square are congruent.
Sometimes
The diagonals of a trapezoid are perpendicular.
Never
The diagonals of a trapezoid bisect each other.
Always
The diagonals of an isosceles trapezoid are congruent.
Always
The intersection of two lines is exactly one point.
Never
The intersection of two planes is a point.
Never
The intersection of two planes is one point.
Sometimes
The opposite angles of a parallelogram are supplementary.
Never
There are more than two right angles in a trapezoid.
Never
There is one right angle in a parallelogram and it is not a rectangle.
Always
Through a point not on a line, one can draw a line parallel to the line.
Always
Two intersecting lines form a plane.
Always
Two isosceles triangles are similar to an equilateral triangle.
Always
Two lines parallel to a third line are parallel to each other.
Sometimes
Two lines parallel to the same plane intersect.
Sometimes
Two lines perpendicular to the same line are parallel.
Sometimes
Two lines skew to a third line are skew to each other.
Sometimes
Two lines that do not intersect are parallel.
Sometimes
Two lines that never intersect are parallel lines.
Always
Two planes that are perpendicular to the same plane are perpendicular to each other.
Always
Two right triangles are similar if both legs of one are proportional to the legs of the other.
