English

In triangle ABC, D and E are points on side AB such that AD = DE = EB. Through D and E, lines are drawn parallel to BC which meet side AC at points F and G respectively. - Mathematics

Advertisements
Advertisements

Question

In triangle ABC, D and E are points on side AB such that AD = DE = EB. Through D and E, lines are drawn parallel to BC which meet side AC at points F and G respectively. Through F and G, lines are drawn parallel to AB which meets side BC at points M and N respectively. Prove that: BM = MN = NC.

Sum
Advertisements

Solution

The figure is shown below

AD = DE = EB

In ΔAEG

AD = DE & DF || EG

Using mid point theorem

F is midpoint of AG

∴ AF = FG         ...(1)

DF || EG || BC and DE = BE,

∴ FG = GC          ...(2)

(1), (2) we get

AF = GF = GC

Similarly since GN || FM || AB

∴ BM = MN = NC

Hence, proved.

shaalaa.com
  Is there an error in this question or solution?
Chapter 12: Mid-point and Its Converse [ Including Intercept Theorem] - Exercise 12 (B) [Page 154]

APPEARS IN

Selina Concise Mathematics [English] Class 9 ICSE
Chapter 12 Mid-point and Its Converse [ Including Intercept Theorem]
Exercise 12 (B) | Q 7 | Page 154

RELATED QUESTIONS

In a ∆ABC, D, E and F are, respectively, the mid-points of BC, CA and AB. If the lengths of side AB, BC and CA are 7 cm, 8 cm and 9 cm, respectively, find the perimeter of ∆DEF.


In Fig. below, M, N and P are the mid-points of AB, AC and BC respectively. If MN = 3 cm, NP = 3.5 cm and MP = 2.5 cm, calculate BC, AB and AC.


Fill in the blank to make the following statement correct

The triangle formed by joining the mid-points of the sides of an isosceles triangle is         


The figure, given below, shows a trapezium ABCD. M and N are the mid-point of the non-parallel sides AD and BC respectively. Find: 

  1. MN, if AB = 11 cm and DC = 8 cm.
  2. AB, if DC = 20 cm and MN = 27 cm.
  3. DC, if MN = 15 cm and AB = 23 cm.

In the figure, give below, 2AD = AB, P is mid-point of AB, Q is mid-point of DR and PR // BS. Prove that:
(i) AQ // BS
(ii) DS = 3 Rs.


D, E and F are the mid-points of the sides AB, BC and CA of an isosceles ΔABC in which AB = BC. Prove that ΔDEF is also isosceles.


Prove that the straight lines joining the mid-points of the opposite sides of a quadrilateral bisect each other.


In a right-angled triangle ABC. ∠ABC = 90° and D is the midpoint of AC. Prove that BD = `(1)/(2)"AC"`.


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.


In AABC, D and E are two points on the side AB such that AD = DE = EB. Through D and E, lines are drawn parallel to BC which meet the side AC at points F and G respectively. Through F and G, lines are drawn parallel to AB which meet the side BC at points M and N respectively. Prove that BM = MN = NC.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×