Question

The Cardinal number of the set A = {quadrilateral with 5 sides} is
A) 1
B) 0
C) 2
D) 4

Answer 1

Hint: Try to find the number of elements in the set A satisfying the condition of quadrilateral, then find the cardinal number. Cardinal number is the number of distinct elements in a finite set.

Complete step by step solution: Since, we have the sides of a quadrilateral as the element of set A.
We know that a quadrilateral consists of four sides and a quadrilateral of five sides never exist. Since, the set A has no solution. Hence, it is an empty set.
A$=\{\ \}$
Cardinal number of A
$=n(A)$
Since there are no elements the Cardinal no 0.

The correct answer is option B.

Note: In mathematics a set is defined as a collection of distinct elements. Additionally, you should know the names of each polygon with a different number of edges. For example, in this question ‘quad’ from the word quadrilateral means four i.e. a polygon with four sides.