A positive-definite matrix is an important concept in linear algebra.

There are times when we perform calculations with the haversine in trigonometry.

He drew an equilateral triangle shape.

He is an expert in orthoepy, teaching pronunciation.

This orthophoto shows the details of the terrain very clearly.

This shape is called a muoctahedron, in other words, a hexagonal four-piece square hole twisted polyhedron.

He was working on that project round the clock.

His words held a double surprise, like 'isseki-rokuto'.

Her name is Izayoi Bara.

He defeated the enemy using the Thirty-Six Stratagems.