Circles Class 10 | NCERT Chapter 10 | Exercise 10.2 Question 9 | Parallel Tangents Theorem

In this video, we solve Exercise 10.2 Question 9 from NCERT Class 10 Maths Chapter – Circles, where: 👉 XY and X'Y' are two parallel tangents to a circle with centre O. 👉 Another tangent AB touches the circle at point C, intersecting XY at A and X'Y' at B. 👉 We need to prove that: ∠AOB = 90°. Through this example, you’ll understand how radii drawn to tangent points are perpendicular, and how parallel tangents help us form a right angle at the centre. 🧠 What You’ll Learn: • Property of tangents drawn from an external point • Radii perpendicular to tangents • Concept of parallel tangents • Step-by-step geometric reasoning to prove ∠AOB = 90° 📐 Key Concepts Used: • OC ⟂ AB • OC ⟂ XY • OC ⟂ X'Y' (Radius drawn to point of contact is perpendicular to the tangent.) Using these perpendiculars and parallel tangent properties, we conclude: ✔️ ∠AOB = 90° An important result for CBSE Class 10 Board Exam (Chapter: Circles) 📥 For Video Lectures & NCERT Solutions of Class 9 & 10 (Maths & Science): Download our Android App: 📱 https://play.google.co[...] 📌 Don’t forget to Like, Share & Subscribe for more helpful videos! 📞 Call us: 999-266-1556 🌐 Visit: www.saraswatividyamandir.com #Class10Maths #NCERTCircles #Exercise10_2 #GeometryProofs #ParallelTangents #CBSE2025