Question

calculating n-fold reflectional symmetry
analyze the reflectional symmetry of the regular polygons.

the square has _____-fold reflectional symmetry.

the regular decagon has _____-fold reflectional symmetry.

Explanation:

Step1: Recall polygon reflection rule

A regular $n$-sided polygon has $n$-fold reflectional symmetry, equal to its number of sides.

Step2: Identify square's side count

A square has 4 sides. So its reflectional symmetry fold count = 4.

Step3: Identify decagon's side count

A regular decagon has 10 sides. So its reflectional symmetry fold count = 10.

Answer:

The square has 4-fold reflectional symmetry.
The regular decagon has 10-fold reflectional symmetry.