2. Questions Bank
  3. 8th Class
  4. Mathematics
  5. Understanding Quadrilaterals

8th Class Mathematics Understanding Quadrilaterals Question Bank Understanding Quadrilaterals

  • question_answer
    In a parallelogram ABCD, if \[AB=2x+5,\]\[CD~=y+1,\] \[AD=y+5~\] and \[BC=3x-4,\]what is the ratio of AB and BC?

    A)  \[71:21\]                            

    B)                         \[12:11\]                                            

    C)                         \[31:35\]                            

    D)                         \[4:7\] 

    Correct Answer: C

    Solution :

    We know that in a parallelogram opposite sides are equal.       \[\therefore \] \[AB=CD\]  or  \[2x+5=y+1\]   and \[AD=BC\] or \[y+5=3x-4\] \[2x-y=-4\]                         ....(i) \[y-3x=-9\]                         .....(ii) Adding (i) and (ii), we get \[-x=-13\]or \[x=13\]and \[y=30\]. Substituting, we have \[AB=31\text{ }cm\] and \[BC=35\text{ }cm\] \[\therefore \] The required ratio \[=31:35\]


You need to login to perform this action.
You will be redirected in 3 sec spinner