# Chapter 6 Class 10 Maths Lecture 4

I find that the harder I work, the more luck I seem to have. – Thomas Jefferson

# Lecture - 4 Chapter 6 Triangles

NCERT Exercise 6.2

Question 9. ABCD is a trapezium in which AB || DC and its diagonals intersect each other at the point O. Show That $\frac{AO}{CO} = \frac{BO}{DO}$.

Question 10. The diagonals of a quadrilateral ABCD intersect each other at the point O such that $\frac{AO}{CO} = \frac{BO}{DO}$ . Show that ABCD is a trapezium.

Proof of AAA Similarity Criterion Theorem 6.3 : If in two triangles, corresponding angles are equal, then their corresponding sides are in the same ratio (or proportion) and hence the two triangles are similar.