Area of Circle with Triangles

| View Cart ⇗ | Info

“In the triangle above, the line AB is its altitude. Since we know how to find the area of one triangle, we can find the areas of as many triangles as we have made from our circle. Therefore, to find the area of a circle: Find the area of one of the triangles and multiply by the number of triangles.” -Foster, 1921

Galleries

Circles

Source

Ellsworth D. Foster ed. The American Educator (vol. 5) (Chicago, IL: Ralph Durham Company, 1921)

Downloads

TIFF (full resolution)

2400×1523, 217.5 KiB

Large GIF

1024×649, 39.0 KiB

Medium GIF

640×406, 21.9 KiB

Small GIF

320×203, 9.7 KiB