Triangle

Shapes

Esther Sarfatti

2007

The wing on a flea

Ed Emberley

1961

Stone age geometry

Gerry Bailey

2014

Shape makers

Michael T. Battista

1998

Solution of triangles

Erik Oberg

1921

Party of three

Christianne C. Jones

2005

Triangles

Bonnie Coulter Leech

2007

Squares and triangles

Kay Robertson

2015