Fundamental Elements of Geometry and Basic Shapes

Flashcards covering fundamental elements of geometry, line relationships, types of angles, triangle classifications, basic 2D shapes, and 3D geometric solids.

What is a point in geometry?

A basic object that marks an exact position in space without size, length, or thickness.

How is a line defined in geometry?

A straight path that extends infinitely in both directions.

What is a plane in geometry?

A completely flat surface that extends infinitely in all directions.

What is a line segment?

A part of a line bounded by two endpoints.

What is a ray?

A part of a line that has a point of origin and extends infinitely in one direction.

What are parallel lines?

Two lines in the same plane that never intersect or touch each other.

What are perpendicular lines?

Two lines that intersect forming a right angle of $90^\circ$.

What is an acute angle?

An angle that measures less than $90^\circ$.

What is a right angle?

An angle that measures exactly $90^\circ$.

What is an obtuse angle?

An angle that measures greater than $90^\circ$ and less than $180^\circ$.

How is a basic triangle defined?

A polygon formed by $3$ sides and $3$ angles.

What is an equilateral triangle?

A triangle with $3$ equal sides.

What is an isosceles triangle?

A triangle with $2$ equal sides.

What is a scalene triangle?

A triangle with no equal sides.

What is an acute triangle?

A triangle with $3$ acute angles measuring less than $90^\circ$.

What is a right triangle?

A triangle with $1$ right angle measuring $90^\circ$.

What is an obtuse triangle?

A triangle with $1$ obtuse angle measuring greater than $90^\circ$.

How is a square defined?

A quadrilateral figure with $4$ equal sides and $4$ right angles.

How is a rectangle defined?

A $4$-sided figure with equal opposite sides and $4$ right angles.

What is a parallelogram?

A $4$-sided figure whose opposite sides are parallel and equal.

How is a circle defined?

A flat, round figure formed by all points that are at the same distance from a center.

What is a cylinder?

A geometric solid with $2$ circular bases and a curved surface connecting them.

What is a cube?

A geometric solid formed by $6$ equal square faces.