Home
Class 14
MATHS
ABCD is a square. Draw an equilateral tr...

ABCD is a square. Draw an equilateral triangle PBC on side BC considering BC is a base and an equilateral triangle QAC on diagonal AC considering AC is a base. Find the value of
`("Area of " Delta PBC)/("Area of " Delta QAC)`.

A

`(1)/(2)`

B

1

C

`(1)/(3)`

D

`(1)/(4)`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to find the areas of triangles PBC and QAC and then calculate the ratio of these areas. ### Step 1: Define the side length of the square Let the side length of square ABCD be \( A \). ### Step 2: Calculate the length of the diagonal AC The diagonal \( AC \) of the square can be calculated using the Pythagorean theorem: \[ AC = \sqrt{A^2 + A^2} = \sqrt{2A^2} = A\sqrt{2} \] ### Step 3: Calculate the area of triangle PBC Triangle PBC is an equilateral triangle with side length equal to the side of the square, which is \( A \). The area of an equilateral triangle is given by the formula: \[ \text{Area} = \frac{\sqrt{3}}{4} \times \text{side}^2 \] Thus, the area of triangle PBC is: \[ \text{Area of } \Delta PBC = \frac{\sqrt{3}}{4} A^2 \] ### Step 4: Calculate the area of triangle QAC Triangle QAC is also an equilateral triangle, but its side length is the diagonal \( AC = A\sqrt{2} \). Using the same area formula: \[ \text{Area of } \Delta QAC = \frac{\sqrt{3}}{4} \times (A\sqrt{2})^2 \] Calculating this gives: \[ \text{Area of } \Delta QAC = \frac{\sqrt{3}}{4} \times 2A^2 = \frac{\sqrt{3}}{2} A^2 \] ### Step 5: Calculate the ratio of the areas Now, we can find the ratio of the areas of triangle PBC to triangle QAC: \[ \frac{\text{Area of } \Delta PBC}{\text{Area of } \Delta QAC} = \frac{\frac{\sqrt{3}}{4} A^2}{\frac{\sqrt{3}}{2} A^2} \] Simplifying this expression: \[ = \frac{\frac{\sqrt{3}}{4}}{\frac{\sqrt{3}}{2}} = \frac{1}{4} \times \frac{2}{1} = \frac{1}{2} \] ### Final Answer The value of the ratio of the areas is: \[ \frac{\text{Area of } \Delta PBC}{\text{Area of } \Delta QAC} = \frac{1}{2} \]
Promotional Banner

Topper's Solved these Questions

  • MENSURATION

    KIRAN PUBLICATION|Exercise TYPE - III|21 Videos
  • MENSURATION

    KIRAN PUBLICATION|Exercise TYPE - IV|169 Videos
  • MENSURATION

    KIRAN PUBLICATION|Exercise Test Yourself|28 Videos
  • LCM AND HCF

    KIRAN PUBLICATION|Exercise Test Yourself |18 Videos
  • MISCELLANEOUS

    KIRAN PUBLICATION|Exercise TYPE-VI|15 Videos

Similar Questions

Explore conceptually related problems

Area of equilateral triangle of side "a" unit is

What is the area of an equilateral triangle of side 10 cm?

Find the area of an equilateral triangle of side 6 cm.

ABCD is a square . Draw a triangle QBC on side BC considering BC as base and draw a triangle PAC on AC as its base such that Delta QBC ~ Delta PAC . Then, ("Area of " Delta QBC)/("Area of " Delta PAC) is equal to :

What is the area of an equilateral triangle with side 2cm?

Find the area of an equilateral triangle whose side is a cm.

KIRAN PUBLICATION-MENSURATION-TYPE -II
  1. The diagonals of two squares are in the ratio of 3:7. What is the rati...

    Text Solution

    |

  2. A string of length 24 cm is bent first into a square and then into a r...

    Text Solution

    |

  3. ABCD is a square. Draw an equilateral triangle PBC on side BC consider...

    Text Solution

    |

  4. If D, E and F are the mid-points of the sides of an equilateral triang...

    Text Solution

    |

  5. The area of a rectangle is 60 cm^(2) and its perimeter is 34 cm, then ...

    Text Solution

    |

  6. The centroid of a triangle Delta ABC is G. If the area of DeltaABC = 7...

    Text Solution

    |

  7. In a trapezium ABCD, AB || CD, AB lt CD, CD = 6 cm and distance betwee...

    Text Solution

    |

  8. In a triangle ABC, AB = 8 cm, AC = 10 cm and angleB = 90^(@), then the...

    Text Solution

    |

  9. In figure, DE || BC. IF DE = 3 cm, BC = 6 cm and area of Delta ADE = 1...

    Text Solution

    |

  10. Delta ABC is a right angled triangle, the radius of its circumcircle i...

    Text Solution

    |

  11. Two equal circles intersect so that their centres, and the points at w...

    Text Solution

    |

  12. Two adjacent sides of a parallelogram are 21 cms and 20 cms. The diago...

    Text Solution

    |

  13. Delta ABC is an equilateral triangle and D and E are midpoints of AB a...

    Text Solution

    |

  14. The perimeters of a square and a rectangle are equal. If their area be...

    Text Solution

    |

  15. A rectangle with one side of length 4 cm. is inscribed in a circle of ...

    Text Solution

    |

  16. If O is the centroid and AD, BE and CF are the three medians of Delta ...

    Text Solution

    |

  17. Delta ABC is similar to Delta DEF. If the ratio of similar sides is k ...

    Text Solution

    |

  18. The height of an equilateral triangle is 18 cm. Its area is ?

    Text Solution

    |

  19. The length and breadth of a rectangular piece of a land are in a ratio...

    Text Solution

    |

  20. The ratio between the area of a square and that of a circle, when the ...

    Text Solution

    |