One part is important.

He was drawing a pentadecagon shape.

Every fifteenth day of the month, our family goes to the temple.

I work five days a week.

This old radio uses a pentode.

My father is thirty-five years old.

This old house was built fifty-six years ago.

Gojuroku always encourages everyone with a smile.

My grandfather retired at the age of fifty-six.

Pentathlon is a competition that tests both physical strength and technique.