One angle of this triangle is 90 degrees.

Mr. Kaku is my best friend.

I saw a crane in the park.

He was building a sand castle on the seashore.

What is the number of strokes in this kanji character?

Mr. Hakkaku is my best friend.

I explained the dative case to him.

In Latin, the ablative case is mainly used to indicate direction, origin, and separation.

His life has experienced a major alteration.

He decided to alter the plan.