The radius of this circle is 5 centimeters.

This computer is using the latest technology.

The Winter Triangle is a shape that connects the brightest stars in the night sky.

He drew a triangle on the blackboard.

We have maintained a good relationship for a long time.

Geomorphology is the science that studies the surface shape of the earth.

Linear algebra is a branch of mathematics that studies the theory of vector spaces and linear transformations.

He has a deep interest in metaphysics.

He is an expert in statistics.

He drew a pentagon on the blackboard.