English

In δAbc, D, E and F Are the Midpoints of Ab, Bc and Ac. If Ae and Df Intersect at G, and M and N Are the Midpoints of Gb and Gc Respectively, Prove that Dmnf is a Parallelogram. - Mathematics

Advertisements
Advertisements

Question

In ΔABC, D, E and F are the midpoints of AB, BC and AC.
If AE and DF intersect at G, and M and N are the midpoints of GB and GC respectively, prove that DMNF is a parallelogram.

Sum
Advertisements

Solution


Consider ΔABC and ΔGBC, by mid-point theorem,
2DF = BC and 2MN = BC
⇒ DF = MN      ....(i)
Consider ΔABG and ΔACG, by mid-point theorem,
2DM = AG and 2FN = AG
⇒ DM = FN     ....(ii)
From (i) and (ii), it is clear that DMNF is a parallelogram.

shaalaa.com
  Is there an error in this question or solution?
Chapter 15: Mid-point and Intercept Theorems - Exercise 15.1

APPEARS IN

Frank Mathematics [English] Class 9 ICSE
Chapter 15 Mid-point and Intercept Theorems
Exercise 15.1 | Q 24.2

RELATED QUESTIONS

In below fig. ABCD is a parallelogram and E is the mid-point of side B If DE and AB when produced meet at F, prove that AF = 2AB.


Fill in the blank to make the following statement correct:

The figure formed by joining the mid-points of consecutive sides of a quadrilateral is           


In the given figure, `square`PQRS and `square`MNRL are rectangles. If point M is the midpoint of side PR then prove that,

  1. SL = LR
  2. LN = `1/2`SQ


In a triangle ABC, AD is a median and E is mid-point of median AD. A line through B and E meets AC at point F.

Prove that: AC = 3AF.


In ΔABC, AB = 12 cm and AC = 9 cm. If M is the mid-point of AB and a straight line through M parallel to AC cuts BC in N, what is the length of MN?


AD is a median of side BC of ABC. E is the midpoint of AD. BE is joined and produced to meet AC at F. Prove that AF: AC = 1 : 3.


ABCD is a parallelogram.E is the mid-point of CD and P is a point on AC such that PC = `(1)/(4)"AC"`. EP produced meets BC at F. Prove that: 2EF = BD.


In ΔABC, X is the mid-point of AB, and Y is the mid-point of AC. BY and CX are produced and meet the straight line through A parallel to BC at P and Q respectively. Prove AP = AQ.


In a parallelogram ABCD, E and F are the midpoints of the sides AB and CD respectively. The line segments AF and BF meet the line segments DE and CE at points G and H respectively Prove that: ΔGEA ≅ ΔGFD


D, E and F are the mid-points of the sides BC, CA and AB, respectively of an equilateral triangle ABC. Show that ∆DEF is also an equilateral triangle.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×