Triangles-Sample Questions

1.  In ΔLMN, ∟L = 50°and ∟N= 60°. If ΔLMN is similar to ΔPQR, then find ∟Q. (AI CBSE 2009)

2.  If areas of two similar triangles are in the ratio 25:64, write the ratio of their corresponding sides. (AI CBSE 2009)

3.  D, E and F are mid points of sides BC, AC and AB respectively of triangle ABC. Find ar(ΔDEF)/ar(ΔABC). ( AI CBSE 2008)

4.  If one diagonal of a trapezium divides the other diagonal in the ratio 1:2. Prove that one of the parallel sides is double the other. (CBSE 2010)

5.  ABC is a right triangle, right angled at A, and D is the mid-point of AB. Prove that BC² = CD² + 3BD². (AI CBSE 2009 C)

6.  If the diagonals of a quadrilateral divide each other proportionally, prove that it is a trapezium. (CBSE 2008)

7.  Triangle ABC is right angled at B and D is the mid-point of BC. Prove that:- AC² = 4AD² . 3AB².(AI CBSE 2008 C)

8.  E is a point on the side AD produced of a parallelogram ABCD and BE intersects CD at F. Show that ΔABC is similar to ΔCFB. (AI CBSE 2008)