English

In the Following Figure, De is Parallel to Bc. Show That: (I) Area ( δAdc ) = Area( δAeb ). (Ii) Area ( δBod ) = Area( δCoe ). - Mathematics

Advertisements
Advertisements

Question

In the following figure, DE is parallel to BC.
Show that: 
(i) Area ( ΔADC ) = Area( ΔAEB ).
(ii) Area ( ΔBOD ) = Area( ΔCOE ).

Sum
Advertisements

Solution

(i) In ΔABC, D is the midpoint of AB and E is the midpoint of AC.
`"AD"/"AB" = "AE"/"AC"`

DE is parallel to BC.
∴ A( ΔADC ) = A( ΔBDC ) = `1/2` A( ΔABC )
Again,
∴ A( ΔAEB ) = A( ΔBEC ) = `1/2` A( ΔABC )

From the above two equations, we have
Area( ΔADC ) = Area( ΔAEB ).
Hence Proved.

(ii) We know that the area of triangles on the same base and between the same parallel lines are equal.
Area( ΔDBC )= Area( ΔBCE )
Area( ΔDOB ) + Area( ΔBOC ) = Area( ΔBOC ) + Area( ΔCOE )
So, Area( ΔDOB ) = Area( ΔCOE ).

shaalaa.com
Figures Between the Same Parallels
  Is there an error in this question or solution?
Chapter 16: Area Theorems [Proof and Use] - Exercise 16 (A) [Page 197]

APPEARS IN

Selina Concise Mathematics [English] Class 9 ICSE
Chapter 16 Area Theorems [Proof and Use]
Exercise 16 (A) | Q 11 | Page 197

RELATED QUESTIONS

In the given figure, AD // BE // CF.
Prove that area (ΔAEC) = area (ΔDBF)


ABCD and BCFE are parallelograms. If area of triangle EBC = 480 cm2; AB = 30 cm and BC = 40 cm.

Calculate : 
(i) Area of parallelogram ABCD;
(ii) Area of the parallelogram BCFE;
(iii) Length of altitude from A on CD;
(iv) Area of triangle ECF.


In the figure given alongside, squares ABDE and AFGC are drawn on the side AB and the hypotenuse AC of the right triangle ABC.

If BH is perpendicular to FG

prove that:

  1. ΔEAC ≅ ΔBAF
  2. Area of the square ABDE
  3. Area of the rectangle ARHF.

Show that:

A diagonal divides a parallelogram into two triangles of equal area.


ABCD is a parallelogram in which BC is produced to E such that CE = BC and AE intersects CD at F.

If ar.(∆DFB) = 30 cm2; find the area of parallelogram.


ABCD is a parallelogram. P and Q are the mid-points of sides AB and AD respectively.
Prove that area of triangle APQ = `1/8` of the area of parallelogram ABCD.


ABCD is a trapezium with AB parallel to DC. A line parallel to AC intersects AB at X and BC at Y.
Prove that the area of ∆ADX = area of ∆ACY.


E, F, G, and H are the midpoints of the sides of a parallelogram ABCD.
Show that the area of quadrilateral EFGH is half of the area of parallelogram ABCD.


The given figure shows a parallelogram ABCD with area 324 sq. cm. P is a point in AB such that AP: PB = 1:2
Find The area of Δ APD.


In ΔABC, E and F are mid-points of sides AB and AC respectively. If BF and CE intersect each other at point O,
prove that the ΔOBC and quadrilateral AEOF are equal in area.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×