My stunning wall by Dennis Brownlee

Midsegment

19dbrownlee — 2018-02-21 19:51:37 UTC

A midsegment is the line segment connecting the midpoints of two sides of a triangle. Since a triangle has three sides, each triangle has three midsegments.

Circumcenter

19dbrownlee — 2018-02-21 19:54:06 UTC

One of several centers the triangle can have, the circumcenter is the point where the perpendicular bisectors of a triangle intersect.

Centroid

19dbrownlee — 2018-02-21 19:56:12 UTC

The center of mass of a geometric object of uniform density.

Altitude

19dbrownlee — 2018-02-21 19:57:51 UTC

The height of an object or point in relation to sea level or ground level.

Median of a Triangle

19dbrownlee — 2018-02-21 20:00:22 UTC

In geometry, a median of a triangle is a line segment joining a vertex to the midpoint of the opposing side, bisecting it.

Exterior angle

19dbrownlee — 2018-02-21 20:04:29 UTC

The angle between a side of a rectilinear figure and an adjacent side extended outward.

Vertex angle

19dbrownlee — 2018-02-21 20:07:13 UTC

In geometry, a vertex angle is the angle associated with a vertex of a polygon.

Concurrent

19dbrownlee — 2018-02-23 16:41:39 UTC

(of three or more lines) meeting at or tending toward one point.

Orthocenter

19dbrownlee — 2018-02-23 16:42:28 UTC

The orthocenter is the point where the three altitudes of a triangle intersect. A altitude is a perpendicular from a vertex to its opposite side.

Base angle

19dbrownlee — 2018-02-23 16:43:44 UTC

The Base Angle Theorem states that in an isosceles triangle, the angles opposite the congruent sides are congruent.

Inequality

19dbrownlee — 2018-02-23 16:46:11 UTC

The relation between two expressions that are not equal, employing a sign such as ≠ “not equal to,” > “greater than,” or < “less than.”.

Interior angle

19dbrownlee — 2018-02-23 16:47:13 UTC

The angle between adjacent sides of a rectilinear figure.

ASA

19dbrownlee — 2018-02-23 16:48:36 UTC

Triangles are congruent if any two angles and their included side are equal in both triangles.

SAS

19dbrownlee — 2018-02-23 16:49:18 UTC

Triangles are congruent if any pair of corresponding sides and their included angles are equal in both triangles.

AAS

19dbrownlee — 2018-02-23 16:50:56 UTC

Triangles are congruent if two pairs of corresponding angles and a pair of opposite sides are equal in both triangles.

SSS

19dbrownlee — 2018-02-23 16:53:58 UTC

Triangles are congruent if all three sides in one triangle are congruent to the corresponding sides in the other.