Right angleIn geometry and trigonometry, a right angle is an angle of exactly 90 degrees or π{\displaystyle \pi }/2radians corresponding to a quarter turn. If a ray is placed so that its endpoint is on a line and the adjacent angles are equal, then they are right angles. The term is a calque of Latinangulus rectus; here rectus means "upright", referring to the vertical perpendicular to a horizontal base line.
Isosceles triangleIn geometry, an isosceles triangle () is a triangle that has two sides of equal length and two angles of equal measure. Sometimes it is specified as having exactly two sides of equal length, and sometimes as having at least two sides of equal length, the latter version thus including the equilateral triangle as a special case. Examples of isosceles triangles include the isosceles right triangle, the golden triangle, and the faces of bipyramids and certain Catalan solids.
RectangleIn Euclidean plane geometry, a rectangle is a rectilinearconvex polygon or a quadrilateral with four right angles. It can also be defined as: an equiangular quadrilateral, since equiangular means that all of its angles are equal (360°/4 = 90°); or a parallelogram containing a right angle. A rectangle with four sides of equal length is a square. The term "" is used to refer to a non-square rectangle. A rectangle with verticesABCD would be denoted as ABCD.
HypotenuseIn geometry, a hypotenuse is the side of a right triangle that is opposite to the right angle. It is always the longest side of the triangle. The other two sides of a right triangle are called legs or catheti. The length of the hypotenuse can be found using the Pythagorean theorem, which states that the square of the length of the hypotenuse equals the sum of the squares of the lengths of the other two sides.
TriangleShape with three sidesTriangle, a polygon with three corners (vertices) and three lines (sides)A triangle or trigon is a polygon consisting of three sides connected at three corners. It is one of the basic shapes in geometry and the simplest of polygons. The corners, also called vertices, are zero-dimensionalpoints while the sides connecting them, also called edges, are one-dimensional line segments.
CathetusIn a right triangle, a cathetus (originally from Greekκάθετος, "perpendicular"; plural: catheti), commonly known as a leg, is either of the sides that are adjacent to the right angle. It is occasionally called a "side about the right angle". The side opposite the right angle is the hypotenuse. In the context of the hypotenuse, the catheti are sometimes referred to simply as "the other two sides".
SquareShape with four equal sides and anglesIn geometry, a square is a regularquadrilateral. It has four straight sides of equal length and four equal angles. Squares are special cases of rectangles, which have four equal angles, and of rhombuses, which have four equal sides. As with all rectangles, a square's angles are right angles (90 degrees, or π/2 radians), making adjacent sides perpendicular.
Degree (angle)A degree (in full, a degree of arc, arc degree, or arcdegree), usually denoted by ° (the degree symbol), is a unit of measurement of a planeangle in which one full rotation is assigned the value of 360 degrees. The unit of angular measure in the International System of Units (SI) is the radian, and one degree is equivalent to π/180 radians. HistoryThe original motivation for choosing the degree as a unit of rotations and angles is unknown.
PerpendicularRelationship between two lines that meet at a right angle The segment AB is perpendicular to the segment CD because the two angles it creates (indicated in orange and blue) are each 90 degrees. The segment AB can be called the perpendicular from A to the segment CD, using "perpendicular" as a noun. The point B is called the foot of the perpendicular from A to segment CD, or simply, the foot of A on CD.
Turn (angle)The turn (symbol tr or pla) is a unit of plane angle measurement that is the measure of a complete angle—the angle subtended by a complete circle at its center. One turn is equal to 2πradians, 360 degrees or 400 gradians. As an angular unit, one turn also corresponds to one cycle (symbol cyc or c) or to one revolution (symbol rev or r). Common related units of frequency are cycles per second (cps) and revolutions per minute (rpm).Edge (geometry)In geometry, an edge is a particular type of line segment joining two vertices in a polygon, polyhedron, or higher-dimensional polytope. In a polygon, an edge is a line segment on the boundary, and is often called a polygon side. In a polyhedron or more generally a polytope, an edge is a line segment where two faces (or polyhedron sides) meet. A segment joining two vertices while passing through the interior or exterior is not an edge but instead is called a diagonal.
DiagonalIn geometry, a diagonal is a line segment joining two vertices of a polygon or polyhedron, when those vertices are not on the same edge. Informally, any sloping line is called diagonal.*As an Amazon Associate I earn from qualifying purchases.