<span>If two parallel planes are cut by a third plane, then the lines of intersection are </span>Parallel.
A parallelogram is a quadrilateral with two pairs of opposite, equal in length and is parallel to one another.
A rectangle is a type of parallelogram.
So, yes, a rectangle is a parallelogram.
Answer:

Step-by-step explanation:
- Simplify




- Find the additive inverse of
by using its property - <em>"Sum of a number & its additive inverse is always zero". </em>Assume that 'x' is an additive inverse of
.


- Simplify




- Now, find the product of
& 


diameter (d) = 2 · r
Circumference (C) = 2 π · r → C = π · d → d = 