It's difficult to calculate the area of this polygon.

Understanding the exposed form is important in learning Japanese.

In Japanese morphology, the inflected form plays an important role.

His new sculpture is in the shape of a helix.

That table is oval-shaped.

He hid himself from the enemy using the art of occult hiding.

She hid the dildo with a shy look.

She hid the dildo, looking embarrassed.

He wrote an ancient poem using the literary language form.

This textbook explains mainly in colloquial form.