It looks like a triangle, because a thick line was used.

它看起来像一个三角形，因为用了粗线条。

youdao

The thick line, I should bring you good advice, as it is.

粗线条的我，竟然把你善意的劝告，看成是很麻烦的事情。

youdao

Clerk: Okay, please fill out each item in the thick line of the application form.

职员：好的，请在这张申请表的粗线部分填表。

youdao

The part that showed above the water line was built of wood sixty centimeters thick.

VOA: special.2009.09.10

So yes, it should be zero at zero, but I made the line too thick.

它在原点处应该是零的，但我这里线画得太粗了。

麻省理工公开课 - 化学原理课程节选

"We now draw a thick line under the Bundesliga season and see now if all the players are fit for the final, " Klopp told AFP after the defeat.

CNN: SHARE THIS

The competing time frames have split the U.S. and Israeli governments since last year, when Mr. Netanyahu stood before the United Nations and drew a thick red line across a drawing of a bomb.

WSJ: Obama Sets Timeline on Iran Nuclear Bomb

She divided the label into two parts, separated by a thick black line, and placed the critical information, such as the name and dosage of the medication, at the top, with everything else relegated to the bottom.

WSJ: When Simplicity Is the Solution