triangle sides
golden ratio triangle
triangle of triangles comments
shape triangle equilateral comments
图片内容是:triangle图片
"彭罗斯三角形(penrose triangle)"的二维设计图由三个截面为正方形的
2 三角形
5509_purpletriangle_01
file:isosceles-triangle-tikz.svg
file:triangle-exteriour-angle-theorem-2.svg