What does this number become when squared?

I have been to Kaesong in North Korea.

Heijo is a beautiful castle built on flatland.

The disposal of feces and urine is important for maintaining public health.

Please check this invoice.

I have to go to the hospital for a urinalysis tomorrow.

The doctor recommended me to carry out a urinalysis.

His success is the result of his personal efforts.

His car was in very bad condition, so he had no choice but to send it for repair.

His health condition is very bad.