Trigonometry math class 10th Lesson 8.1 question No 9.br class 10 math chapter 8.1 Trigonometry questions No 9br with solutions. br दोस्तों हमलोग इस वीडियो में बिहार बोर्ड के 10वीं कक्षा का br गणित पढेंगे, पाठ का नाम- त्रिकोंमिति, ChapterLesson- 8.1. question No- 9br bihar board math for class 10. ncert maths class 10th.br class 10 math. trigonometry class 10th math. class 10 math chapter 8.1 class 10th math lesson 8.1br bihar board math class 10 chapter 8.1br br #Trigonometry br #ClassXmathbr #त्रिकोणमितिbr br Trigonometry (from Greek trigōnon, "triangle" and metron, "measure") is a branch of mathematics that studies relationships between side lengths and angles of triangles. The field emerged in the Hellenistic world during the 3rd century BC from applications of geometry to astronomical studies.