He measured the size of the room.

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

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

It's difficult to guess his feelings.

He likes to observe celestial bodies.

The astronomer conducted an observation of the night sky.

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.