He was drawing a figure using a set square.

Triangulum is one of the beautiful constellations shining in the autumn night sky.

He yelled at me, looking at me with fury.

Please throw the leftover food in the triangular sink basket in the kitchen.

There is a complex love triangle between them.

He is good at solving trigonometry problems.

Trigonometric functions are one of the basic concepts in mathematics.

He is good at solving problems of trigonometric functions.

He trains his deltoid muscles at the gym every day.

The calculation of determinants is an important part of mathematics.