He used a stick to measure the depth of the river.

He measured the size of the room.

The astronomer conducted an observation of the night sky.

He likes to observe celestial bodies.

It's difficult to guess his feelings.

To measure your underbust size, you measure around the lower part of your chest with a tape measure.

The children were playing in the park, encircling a tree.

He used a tape measure to measure the length of the desk.

What is the size of this shirt?

The lower part of his jeans was dirty with mud.