Fundamentals of Geometry for Secondary or High School [P2]

Name: Fundamentals of Geometry for Secondary or High School [P2]
Rating: 5.0 (1 reviews)

Part 2: Right Angles and Angles of a Triangle

Created byMathematikos Mathematikos

Last updated 11/2025

English

What you'll learn

Understand geometry thoroughly thru illustrated solved problems.
Understand the concepts and postulates of a right triangle.
Illustrate the concepts and postulates of angles in a triangle.
Analyze and solve examination-like problems.
Illustrate and apply the underlying concepts and laws of geometry.

Course content

4 sections • 25 lectures • 1h 18m total length

See the Part 1 of this course in the link (Resources)0:18
Hello Everyone!
Welcome to the course Geometry for Secondary or High School. In this course you will learn each topic through solved examples or exercises.
On the other hand, the free courses have a limited number of videos that can be uploaded so you will be directed to YouTube.
Nonetheless, the learning and fun will continue.
Lastly, messages and questions are welcome.
Cheers!!

Right Angles5:09
Right Angles Solved Exercise 12:20
Observe that line k and line L are both perpendicular to line v. Conclude that line k is perpendicular to line L, illustrating the theorem about perpendicular lines.
Right Angles Solved Exercise 22:31
Right Angles Solved Exercise 35:17
Show how right angles and perpendicular relationships lead to equal angle measures, proving that angle a equals angle b by comparing sums to 90 degrees.
Right Angles Solved Exercise 40:07
To access the comprehensive tutorial, visit the YouTube playlist:
https://www.youtube.com/channel/UC64AP-nNy2vezHrEYJkhIdA

Thank you very much for your time.
To support the channel, consider subscribing.
To be updated with new videos and content, just follow the channel.
Cheers. Thank you.
Let's have fun!!

Angles of a Triangle11:53
Review on Parallel and Opposite Angles4:31
Explore how two parallel lines cut by a straight line produce parallel angles and alternate angles, show opposite angles are equal, and explain supplementary angles summing to 180 degrees.
Angles of a Triangle Solved Exercise 12:54
Explore solving for angle c in a right triangle using fact that the sum of the non-right angles equals 90 degrees, with angle b values 34, 60, 30, and 45.
Angles of a Triangle Solved Exercise 23:34
Compute angle c using the triangle angle sum: c = 180 minus a minus b. Apply this to the A, B, C, D examples.
Angles of a Triangle Solved Exercise 37:16
Angles of a Triangle Solved Exercise 46:14
Explore solving for x using parallel lines and transversals, along with the triangle angle sum. Apply quadrilateral and parallelogram properties to determine angle measures.
Angles of a Triangle Solved Exercise 53:13
Solve angle x problems with parallel lines and transversals using the theorem of parallel lines and linear angles to find 73° in one figure and 50° in the other.
Angles of a Triangle Solved Exercise 64:21
Angles of a Triangle Solved Exercise 74:36
Angles of a Triangle Solved Exercise 85:16
Angles of a Triangle Solved Exercise 95:00
Angles of a Triangle Solved Exercise 103:16
Show that an exterior angle of a triangle equals the sum of the two opposite interior angles by combining the linear pair property with the triangle angle-sum.
Angles of a Triangle Solved Exercise 110:07
To access the comprehensive tutorial, visit the YouTube playlist:
https://www.youtube.com/channel/UC64AP-nNy2vezHrEYJkhIdA

Thank you very much for your time.
To support the channel, consider subscribing.
To be updated with new videos and content, just follow the channel.
Cheers. Thank you.
Let's have fun!!
Angles of a Triangle Solved Exercise 120:07
To access the comprehensive tutorial, visit the YouTube playlist:
https://www.youtube.com/channel/UC64AP-nNy2vezHrEYJkhIdA

Thank you very much for your time.
To support the channel, consider subscribing.
To be updated with new videos and content, just follow the channel.
Cheers. Thank you.
Let's have fun!!
Angles of a Triangle Solved Exercise 130:07
To access the comprehensive tutorial, visit the YouTube playlist:
https://www.youtube.com/channel/UC64AP-nNy2vezHrEYJkhIdA

Thank you very much for your time.
To support the channel, consider subscribing.
To be updated with new videos and content, just follow the channel.
Cheers. Thank you.
Let's have fun!!
Angles of a Triangle Solved Exercise 140:07
To access the comprehensive tutorial, visit the YouTube playlist:
https://www.youtube.com/channel/UC64AP-nNy2vezHrEYJkhIdA

Thank you very much for your time.
To support the channel, consider subscribing.
To be updated with new videos and content, just follow the channel.
Cheers. Thank you.
Let's have fun!!
Angles of a Triangle Solved Exercise 150:07
To access the comprehensive tutorial, visit the YouTube playlist:
https://www.youtube.com/channel/UC64AP-nNy2vezHrEYJkhIdA

Thank you very much for your time.
To support the channel, consider subscribing.
To be updated with new videos and content, just follow the channel.
Cheers. Thank you.
Let's have fun!!
Angles of a Triangle Solved Exercise 160:07
Explore angles of a triangle through solved exercise 16, applying core geometry concepts for high school learners.

Requirements

Elementary or basic algebra.
Nonetheless, you will learn everything you need to know through solved exercises.

Description

Imagine reading an entire geometry textbook for secondary or high school and solving most of the exercises. Wow, that’s amazing! Well, that’s exactly what you’ll achieve if you enroll in this course. It is based on a comprehensive collection of geometry books. Every topic from these books has been carefully compared, compiled, and discussed, with most of the challenging and essential exercises solved for you.

If you’ve ever wished for more solved examples, then this course is perfect for you! While many other courses offer lectures, very few provide an abundance of solved exercises or examples. This course can serve as a supplementary resource or even as a primary reference to help you understand geometry for secondary or high school. It includes concept overviews and, most importantly, plenty of solved exercises. These exercises are designed to enhance your understanding of concepts, postulates, and axioms in a clear and practical way.

This is the second part (Part 2: Right Angles and Angles of a Triangle) for the subject Geometry in high school or secondary. Enrol and follow the author for more future contents.

The author’s aim is simple, that is to teach mathematics by comprehension. As the world and generation changed, the teaching style must follow. This is what we call the innovation in teaching. To do that, a simple brief lecture must be followed by lots and lots of examples applying the mathematics topic that have been discussed. In that manner, the knowledge is transferred by showing them how the theorem and axioms work.

The author deeply believes that mathematics is a great tool for advancement and discovering things. Through this innovation of teaching, the tools have been presented and it’s up to the future generation on how they are going to use these tools in order to improve life, hopefully.

Thank you very much and have fun!..

Note: If you are under 18 years old, please seek advice and guidance from your parents or guardian in enrolling in the course. Thank you. Share this course to your friends, relatives and families. Sharing is caring.

Note: Please. Please. Please, no reproduction of this work. This can be used in classroom lectures but please no reproduction. Please. You can also use the videos in the YouTube channel but please no reproduction. Thank you very much for your understanding.

Who this course is for:

Students who want more and more examples or solved exercises to learn thoroughly the topics in geometry.
Students who want to ace or just pass the examinations.
Supplementary to teachers and lecturers subject materials.
Homeschool or home education.

Fundamentals of Geometry for Secondary or High School [P2]

What you'll learn

Explore related topics

Course content

Enroll to the Part 1: Lines, Distance, Angles and Proofs1 lecture • 1min

Right Angles5 lectures • 15min

Angles of a Triangle18 lectures • 1hr 3min

Enroll to the Part 3: Coordinate Systems, Distance bet Pt and Equation of a Line1 lecture • 1min

Requirements

Description

Who this course is for: