What is Geometry?

Geometry is a branch of mathematics which deals with the properties, measurement, and relationships of lines, angles, points, coordinates, solids and surfaces, and solids. It is the 4th math course in high school that will help you guide through among other things inclusive of points, planes, parallel lines, lines, angles, quadrilaterals, triangles, squares, similarity, trigonometry, transformations, circles, circumference and area. Learning geometry, you will be able to study the properties of given elements that remain invariant under particular transformations.

Major Branches of Geometry

1. Euclidean Geometry

In ancient cultures there developed a type of geometry apt to the relationships between lengths, areas, and volumes of physical figures. This geometry gained popularity being codified in Euclid’s elements based upon 10 axioms, or postulates, from which a hundred many theorems were proved by deductive logic.

2. Non-Euclidean Geometries

Several mathematicians substituted alternatives to Euclid’s parallel postulate, which, in its modern form, reads, “Given a line and a point not on the line, it is feasible to construct exactly one line along the given point parallel to the line.”

3. Analytic Geometry

Introduced by the French mathematician René Descartes (1596–1650), this geometry is representative of algebraic equations. This French mathematician only initiated rectangular coordinates to locate points and to allow lines and curves to be delineated with algebraic equations.

4. Projective Geometry

The French mathematician Girard Desargues (1591–1661) initiated projective geometry to enable dealing with those properties of geometric objects that are not revised by projecting their image, or “shadow,” on another surface.

5. Differential Geometry

In connection with practical problems of surveying and geodesy, a German mathematician introduced the domain of differential geometry. Using differential calculus, the innate properties of curves and surfaces are distinguished. For example, he characterized that the intrinsic curvature of a cylinder is just similar as that of a plane, as can be observed by cutting a cylinder through its axis and flattening, but not similar as that of a sphere, which is unable to be flattened without distortion.

6. Topology

Topology, the youngest and most innovative branch of geometry, emphasizes upon the properties of geometric shapes that remain unaltered upon ongoing deformation—stretching, contracting, and folding, but not tearing.

Geometry Mathematics

Let’s get to know what you will be learning under concepts of geometry:


  • Rays, Lines and line segments

  • Measuring Lines

  • Parallel, perpendicular, points, and planes

  • Geometry definitions

  • The golden ratio


  • Properties and Classification of geometric shapes

  • Equal parts of shapes

  • Polygons and Angles with polygons

  • Curves

  • Solid geometry (3D shapes)


  • Introduction to Angles

  • Measuring and Constructing Angles

  • Angles between bisecting lines

  • Types of Angles

  • Angles in circle 


  • Types of Triangles

  • Triangle angles

  • Triangle inequality theorem

  • Angle bisectors and Perpendicular bisectors

  • Altitudes, Medians & centroids


  • Types of Quadrilaterals

  • Proofs & angles of Quadrilaterals

Coordinate Plane

  • Coordinate plane: Quadrants on the coordinate plane, quadrant 1 and 4 quadrants

  • Reflecting points on coordinate plane

  • Quadrilaterals and Polygons on the coordinate plane

Area and Perimeter

  • Count unit squares to find area

  • Area of rectangles, trapezoids and Area of parallelograms

  • Area of triangles

  • Area of shapes on grids

  • Area of composite figures

  • Area and circumference of circles

  • Advanced area with triangles

Volume and Surface Area

  • Volume of rectangular prisms

  • Volume with fractions

  • Surface area

  • Surface and volume density

  • Volume of spheres, cones, and cylinders

  • Volume and surface area of Solid geometry

  • Cross sections of 3D objects

  • Koch snowflake fractal

  • Heron's formula


  • Introduction to rigid transformations

  • Properties and definitions of transformations

  • Dilations, Translations, Rotations and Reflections of Transformations

  • Overview of Rigid transformations

  • Symmetry


  • Introduction and Definition of Similarity

  • triangle similarity

  • Solving similar triangles

  • Angle bisector theorem

  • Solving with similar and congruent triangles

  • Solving modeling problems


  • Transformations and congruence

  • Triangle congruence

  • Theorems in reference to triangle properties and quadrilateral properties

  • Working with triangles

  • Proofs of general theorems that apply triangle congruence


  • Introduction to the trigonometric ratios

  • Special right triangles

  • Modeling with right triangles

  • Solving for a side and for an angle in a right triangle using the trigonometric ratios

  • Trigonometric ratios and similarity

  • The law of sines and cosines

  • Sine and cosine of complementary angles

  • The reciprocal trigonometric ratios

  • Solving problems on general triangles


  • Circle basics

  • Introduction to radians

  • Arc measure, Arc length (from degrees), Arc length (from radians)

  • Sectors

  • Problem solving on Inscribed angles and Inscribed shapes

  • Properties of tangents

  • Area of inscribed triangle

  • Standard and Expanded equation of a circle

Analytic Geometry

  • Distance and midpoints

  • Dividing line segments

  • Distance on the coordinate plane Problem solving

  • Parallel and perpendicular lines

  • Distance between a point and a line challenge

Geometric Constructions

  • Constructing bisectors of lines and angles

  • Constructing regular polygons

  • Constructing inscribed in circles

  • Constructing incircles and circumcircles

  • Constructing a line tangent to a circle

Pythagorean Theorem

  • Introduction and Application of Pythagorean theorem

  • Pythagorean theorem and distance between points

  • Pythagorean theorem proofs


  • Worked examples pr problem solving

FAQs (Frequently Asked Questions)

Q1. What is the History Behind Geometry?

Answer:  The earliest known unambiguous examples begun with devising mathematical rules and methods useful for constructing buildings, surveying land areas, and measuring storage containers. The Greeks around 6th century BCE collected and delivered this practical knowledge and generalized it in the form of the abstract subject now known as geometry. It is derived from the summation of the Greek words geo (“Earth”) and metron (“measure”) for the measurement of the Earth.

 Q2. What are the Various Geometric Concepts?

Answer: There are majorly 10 geometrical concepts. Geometry guides you through among other elements that include:

  • Points

  • Planes

  • parallel lines

  • Lines

  • Angles

  • Triangles

  • Similarity

  • Trigonometry

  • Transformations

  • Quadrilaterals

  • circles and area.

Q3. What is the Geometric Concept of Finding the Right Angle?

Answer: Builders and surveyors in ancient times required to construct right angles onto the field. The technique used by the Egyptians gained them the name “rope pullers” in Greece, might be because they used a rope for laying out their construction.

Q4. Which Ancient Method Helps Finding the Right Angle?

Answer: The simplest method to conduct the trick is to take a rope that is 12 units long, mark knot 3 units from one end and another 5 units from the other end, and then knot the ends together to form a loop. However, the Egyptian scribes generalize them to obtain the Pythagorean Theorem: the square on the line opposite the right angle is equivalent to the sum of the squares on the other two sides.