What does XY plane mean?

What are the differences between similar triangles and congruent triangles?

What are Armstrong numbers?

All real numbers are rational numbers.

A) True

B) False

The L.C.M of the smallest 2 digit composite number and the smallest composite number is:

• (a) 12
• (b) 4
• (c) 20
• (d) 44

Are all natural numbers also whole numbers?