Question

in triangle ABC,DE are the mid points of the sides AB and AC respectively . express de interm of BC

Answer 1

given-
d is the m.p. of AB & e is the m.p. of AC
according to  mid point theorem de is ll to BC and 1/2 of it
so, de= 1/2*BC
 (:-:) -------------------------hope this helps--------------------------- (:-:)

Answer 2

According to the midpoint theorem,
The line segment joining midpoints of any two sides of a triangle is always parallel to it and also half of it. 

Since, D and E are the midpoints of AB and AC 
Therefore, DE || BC and also DE = 1/2 BC