Class 9 Maths | I’m Up and Down, and Round and Round | Basics of Circles + Circumcircle + Ex.5.1

Class 9 Maths | I’m Up and Down, and Round and Round | Basics of Circles + Circumcircle Construction + Exercise 5.1 | CBSE 2026–27 Welcome to Rishikesh Education Academy (REA)! In this video, we begin the chapter “I’m Up and Down, and Round and Round” for Class 9 CBSE Mathematics with a complete conceptual explanation. This lecture is designed to build a strong foundation for school exams and future competitive exams. 📚 In this video, you will learn: ✅ Basic definitions related to circles ✅ Circle, Radius, Diameter, Chord, Arc, Sector & Segment ✅ Circumcentre and Circumcircle explained clearly ✅ Construction of the Circumcircle of: Acute-angled Triangle Right-angled Triangle Obtuse-angled Triangle ✅ Complete solutions of Exercise 5.1 (All 5 Questions) with detailed step-by-step explanations 00:00 Introduction 01:05 Basic Terms Related to Circle 03:38 Symmetry of a Rectangle 04:36 Symmetry of a Square 05:26 Symmetry of a Circle 06:37 How Many Circles Can Pass Through two given Points? 09:25 Collinear and Non-Collinear Points 10:28 Theorem 1 17:08 Construction of Circumcircle of an Acute-Angled Triangle 20:25 Construction of Circumcircle of an Obtuse-Angled Triangle 25:22 Construction of Circumcircle of a Right-Angled Triangle 29:15 Ex. 5.1 – Question 1 35:11 Exercise 5.1 – Question 2 40:01 Exercise 5.1 – Question 3 43:57 Exercise 5.1 – Questions 4 This video is perfect for: 📖 CBSE Class 9 Students 🏫 School Examination Preparation 💯 Concept Building 🎯 Students who want to master Geometry from the basics If you find this lecture helpful, don’t forget to: 👍 Like the video 💬 Comment your doubts 📤 Share it with your friends 🔔 Subscribe to Rishikesh Education Academy (REA) for more quality Mathematics lectures. #Class9Maths #CBSEClass9 #Circles #Geometry #Circumcircle #Circumcentre #Exercise5_1 #Mathematics #CBSE2026 #CBSE2027 #RishikeshEducationAcademy #REA #MathsWithVikashSemwal