Question

In a parallelogram ABCD, if AB=2x+5, CD=y+1, AD=y+5 and BC=3x-4 then the ratio of AB:BC is

• A. 71:21
• B. 12:11
• C. 31:35
• D. 4:7

Answer 1

The correct option is C 31:35

In parallelogram , opposite sides are congruent

Then AB=CD...2x+5=y+1.....2x-y=-4 .............(1)

And AD+BC.....y+5=3x-4........-3x+y=-4-5=-9...........(2)

Substructure (1) in to (2)

-x=-13 Or x=13

And y=-4-26=30

Then AB=CD =$2\times 13+5=31$

And AD+BC=$3\times 13-4=35$

AB:AD=31:35