If `D ,E ,F` are the mid-points of the sides `B C ,C Aa n dA B` respectively of a triangle `A B C ,` prove by vector method that `A r e aof D E F=1/4(a r e aof A B C)dot`

D ,\ E ,\ F are the mid-points of the sides B C ,\ C A and A B respectively of a A B C . Determine the ratio of the areas of D E F and A B C .

If O is a point in space, A B C is a triangle and D , E , F are the mid-points of the sides B C ,C A and A B respectively of the triangle, prove that vec O A + vec O B+ vec O C= vec O D+ vec O E+ vec O Fdot

D ,\ E ,\ F are the mid-point of the sides B C ,\ C A\ a n d\ A B respectively of A B Cdot Then D E F is congruent to triangle. A B C (b) AEF (c) B F D ,\ C D E (d) A F E ,\ B F D ,\ C D E

Let A B C be an isosceles triangle in which A B=A Cdot If D ,\ E ,\ F be the mid-points of the sides B C ,\ C A\ a n d\ A B respectively, show that the segemtn A D\ a n d\ E F bisect each other at right angles.

In a A B C ,\ D ,\ E ,\ F are the mi-points of sides B C ,\ C A\ a n d\ A B respectively. If a r( A B C)=16 c m^2, then a r\ (t r a p e z i u m\ F B C E)= 4\ c m^2 (b) 8\ c m^2 (c) 12 c m^2 (d) 10 c m^2

In an equilateral triangle, prove that the centroid and centre of the circum-circle (circum centre) coincide) Given : An equilateral triangle A B C in which D , E a n d F are the mid-points of sides B C , C A a n d A B respectively. To Prove: The centroid and circum centre are coincident. Construction : Draw medians A D , B E a n d C F

In Figure, A B C D is a parallelogram. E\ a n d\ F are the mid-points of the sides A B\ a n d\ C D respectively. Prove that the line segments A F\ a n d\ C E trisect (divide into three equal parts) the diagonal B D .

D, E and F are respectively the mid-points of the sides BC, CA and AB of aDeltaA B C . Show that (i) BDEF is a parallelogram. (ii) a r" "(D E F)=1/4a r" "(A B C) (iii) a r" "(B D E F)=1/2a r" "(A B C)

In a parallelogram A B C D ,E ,F are any two points on the sides A B and B C respectively. Show that a r( A D F)=a r( D C E)dot

In a A B C ,\ E\ a n d\ F are the mid-points of A C\ a n d\ A B respectively. The altitude A P\ to\ B C intersects F E\ at Qdot Prove that A Q=Q P