Home
Class 9
MATHS
In parallelogram ABCD, E is a point in A...

In parallelogram ABCD, E is a point in AB and DE meets diagonal AC at point F. If DF:FE= `5:3` and area of `DeltaADF` is `60cm^(2)`, find :
(i) area of `DeltaADE`
(ii) if AE:EB= `4:5`, find the area of `DeltaADB`
(iii) also, find area of parallelogram ABCD.

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem step by step, we will break it down into three parts as per the question. ### Given Information: - In parallelogram ABCD, E is a point on AB. - DE meets diagonal AC at point F. - DF:FE = 5:3 - Area of triangle ADF = 60 cm² ### (i) Find the area of triangle ADE 1. **Understanding the relationship between triangles ADF and AFE:** - Triangles ADF and AFE share the same vertex A and have the same base DE. - Therefore, the ratio of their areas is equal to the ratio of their corresponding segments on line DE. 2. **Setting up the ratio:** - Given DF:FE = 5:3, we can denote the area of triangle AFE as \( x \). - Thus, we have: \[ \frac{\text{Area of } \triangle ADF}{\text{Area of } \triangle AFE} = \frac{DF}{FE} = \frac{5}{3} \] - Substituting the known area of triangle ADF: \[ \frac{60}{x} = \frac{5}{3} \] 3. **Cross-multiplying to find x:** \[ 60 \cdot 3 = 5 \cdot x \implies 180 = 5x \implies x = \frac{180}{5} = 36 \text{ cm}^2 \] 4. **Finding the area of triangle ADE:** - Area of triangle ADE = Area of triangle ADF + Area of triangle AFE \[ \text{Area of } \triangle ADE = 60 + 36 = 96 \text{ cm}^2 \] ### (ii) If AE:EB = 4:5, find the area of triangle ADB 1. **Understanding the relationship between triangles ADE and EDB:** - Triangles ADE and EDB share the same vertex D and lie on the same line AD. - Therefore, the ratio of their areas is equal to the ratio of AE to EB. 2. **Setting up the ratio:** - Let the area of triangle EDB be \( y \). - Given AE:EB = 4:5, we have: \[ \frac{\text{Area of } \triangle ADE}{\text{Area of } \triangle EDB} = \frac{AE}{EB} = \frac{4}{5} \] - Substituting the known area of triangle ADE: \[ \frac{96}{y} = \frac{4}{5} \] 3. **Cross-multiplying to find y:** \[ 96 \cdot 5 = 4 \cdot y \implies 480 = 4y \implies y = \frac{480}{4} = 120 \text{ cm}^2 \] 4. **Finding the area of triangle ADB:** - Area of triangle ADB = Area of triangle ADE + Area of triangle EDB \[ \text{Area of } \triangle ADB = 96 + 120 = 216 \text{ cm}^2 \] ### (iii) Find the area of parallelogram ABCD 1. **Using the relationship between triangle ADB and parallelogram ABCD:** - The area of triangle ADB is half of the area of parallelogram ABCD. \[ \text{Area of } \triangle ADB = \frac{1}{2} \times \text{Area of parallelogram ABCD} \] - Substituting the area of triangle ADB: \[ 216 = \frac{1}{2} \times \text{Area of parallelogram ABCD} \] 2. **Solving for the area of parallelogram ABCD:** \[ \text{Area of parallelogram ABCD} = 216 \times 2 = 432 \text{ cm}^2 \] ### Final Answers: (i) Area of triangle ADE = 96 cm² (ii) Area of triangle ADB = 216 cm² (iii) Area of parallelogram ABCD = 432 cm²
Promotional Banner

Topper's Solved these Questions

  • AREA THEOREMS

    ICSE|Exercise Exercies 16(B)|16 Videos
  • AREA AND PERIMETER OF PLANE FIGURES

    ICSE|Exercise EXERCISE 20(D)|12 Videos
  • CHAPTER REVISION (STAGE 2)

    ICSE|Exercise DISTANCE FORMULA |12 Videos

Similar Questions

Explore conceptually related problems

In parallelogram ABCD, P is mid-point of AB. CP and BD intersect each other at point O. If area of DeltaPOB=40cm^(2) and OP:OC= 1:2 , find : (i) Areas of DeltaBOC and DeltaPBC (ii) Areas of DeltaABC and parallelogram ABCD.

ABCD is a parallelogram. Find the ratio of the area of Delta ABC to the area of the parallelogram ABCD.

In parallelogram ABCD above, AC=3 and AD=5. What is the area of ABCD?

In the given figure, if the area of parallelogram ABCD is 40 cm^2 , find the area of parallelogram ABEF

In parallelogram ABCD, AB = 16 cm, BC = 12 cm and diagonal AC = 20 cm. Find the area of the parallelogram.

In the given figure, ABCD is a parallelogram whose area is 60 cm^(2) . Find the area of DeltaACB

In the following figure, OAB is a triangle and AB////DC . If the area of DeltaCAD=140cm^(2) and the area of DeltaODC=172cm^(2) , find (i) the area of DeltaDBC (ii) the area of DeltaOAC (iii) the area of DeltaODB .

In Delta ABC , E is mid-point of side AB and EBCD is a parallelogram. If the area of Delta ABC is 80 cm, find the area of parallelogram EBCD.

ABCD is a parallelogram in which BC is produced to E such that CE=BC and AE intersects CD at F. If ar.(DeltaDFB)=30cm^(2) , find the area of parallelogram

In a parallelogram ABCD, point P lies in DC such that DP:PC= 3:2 . If area of DeltaDPB=30sq. cm, ffind the area of the parallelogram ABCD.

ICSE-AREA THEOREMS-Exercies 16(C )
  1. In triangleABC,E and F are mid-points od sides AB and AC respectively....

    Text Solution

    |

  2. In parallelogram ABCD, P is mid-point of AB. CP and BD intersect each ...

    Text Solution

    |

  3. The medians of a triangle ABC intersect each other at point G. If one ...

    Text Solution

    |

  4. The perimeter of a triangle is 300 mdot If its sides are in the ...

    Text Solution

    |

  5. In parallelogram ABCD, E is a point in AB and DE meets diagonal AC at ...

    Text Solution

    |

  6. In the following figure, BD is parallel to CA, E is mid-point of CA an...

    Text Solution

    |

  7. In the following figure, OAB is a triangle and AB////DC. If the area...

    Text Solution

    |

  8. E, F, G and H are the mid-points of the sides of a parallelogram ABCD....

    Text Solution

    |

  9. ABCD is a trapezium with AB parallel to DC. A line parallel to AC inte...

    Text Solution

    |

  10. In the given figure, the diagonals AC and BD intersects at point O. If...

    Text Solution

    |

  11. The given figure shows a parallelogram ABCD with area 324sq. cm. P is ...

    Text Solution

    |

  12. In triangleABC,E and F are mid-points od sides AB and AC respectively....

    Text Solution

    |

  13. In parallelogram ABCD, P is mid-point of AB. CP and BD intersect each ...

    Text Solution

    |

  14. The medians of a triangle ABC intersect each other at point G. If one ...

    Text Solution

    |

  15. The perimeter of a triangle ABC is 37 cm and the ratio between the len...

    Text Solution

    |

  16. In parallelogram ABCD, E is a point in AB and DE meets diagonal AC at ...

    Text Solution

    |

  17. In the following figure, BD is parallel to CA, E is mid-point of CA an...

    Text Solution

    |

  18. In the following figure, OAB is a triangle and AB////DC. If the area...

    Text Solution

    |

  19. E, F, G and H are the mid-points of the sides of a parallelogram ABCD....

    Text Solution

    |

  20. ABCD is a trapezium with AB parallel to DC. A line parallel to AC inte...

    Text Solution

    |