Pronunciation: /kɒnˈvɛks/ Explain
A shape is convex if a
that is drawn between any two points in the shape is completely
within the shape.
Figure 1: A disc is convex
Figure 1 is an example of a convex shape, in this case a disc. Since it is not possible to pick two
points within the shape and draw a line between them that leaves the shape, the shape is convex.
Figure 2: Concave shape
Figure 2 is an example of a
shape. Note that the entire line is not contained within the disc.
Discovery - Is a spherical solid convex or concave?
A spherical solid is a three dimensional shape with a sphere as the outer edge. Is a
spherical solid concave or convex? Imagine a sphere. Can you imagine a straight line
between any two points in the spherical solid that is partly outside the solid?
Click here to see the answer.
A sphere is convex.
A bear wanted a nice cozy cave in which to spend the winter.
She found a rock sticking out of the ground, but it vexed her that
the rock was convex. She continued to look. Then she found a cave.
It was concave, so she crawled in and went to sleep for the winter.
- McAdams, David E.. All Math Words Dictionary, convex. 2nd Classroom edition 20150108-4799968. pg 47. Life is a Story Problem LLC. January 8, 2015. Buy the book
- Convex. Geometry Glossary. American Mathematical Society. Last Accessed 6/25/2018. http://www.ams.org/featurecolumn/archive/geometry-glossary.html.
- Beman, Wooster Woodruff; and Smith, David Eugene. New Plane and Solid Geometry. pg 54. www.archive.org. Ginn & Company. 1899. Last Accessed 6/25/2018. http://www.archive.org/stream/newplaneandsoli02smitgoog#page/n69/mode/1up/search/convex. Buy the book
- Lyman, Elmer A.. Plane and Solid Geometry. pg 57. www.archive.org. American Book Company. 1908. Last Accessed 6/25/2018. http://www.archive.org/stream/planesolidgeomet00lymarich#page/57/mode/1up/search/convex. Buy the book
Cite this article as:
McAdams, David E. Convex. 12/21/2018. All Math Words Encyclopedia. Life is a Story Problem LLC. http://www.allmathwords.org/en/c/convex.html.
12/21/2018: Reviewed and corrected IPA pronunication. (McAdams, David E.)
6/25/2018: Removed broken links, updated license, implemented new markup, updated GeoGebra apps. (McAdams, David E.)
1/18/2010: Added "References". (McAdams, David E.)
7/10/2008: Added click here to see answer. (McAdams, David E.)
7/1/2008: Initial version. (McAdams, David E.)