Rectilinear Figures


   
 
Theorem 4
If a pair of opposite sides of a quadrilateral is equal and parallel, it is a parallelogram.
 
 
ABCD is a quadrilateral. AB || DC and AB = DC.
 
 
ABCD is a parallelogram.
 
BC || AD
 
 
Join AC and name the angles as shown
 
 
 
 
 
We may use numbers or alphabets while referring to angles to make the proof easy.
 
 
     
   
Get unlimited tutoring in Math, English, Physics, Chemistry, Biology, Algebra, Geometry and all other subjects at $99.99 per month!

(100% money-back guarantee)

Customer Care

Click to get customer service, technical support and subscription help.

Customer Care Chat


Refer-A-Friend

Get One Month Free!
When you refer a friend