By Mr. Dunfee

THE SUM OF THE ANGLES OF ATRIANGLE IS 180 DEGREES.

Classifying triangles according to the measureof the angles of the triangle.

All 3 angles measure less than 90 degrees.

One angle measures 90 degrees and the other twoangles are acute.

One angle that measures more than 90 degrees and the other two are acute.

Classifying triangle according to the lengthof the sides of the triangles.

The lengths of the sides are not congruent. The lengths are not equal in size.

The lengths of two sides are congruent.

The lengths of all threesides are equal in size which means they are congruent.

Congruent triangles are triangles that are equal in size and shape. They have the same length of the sides and have the same measure of the angles.

Side Angle Side

Side Side Side

Angle Side Angle

Polygons

A polygon is a many sided closed figure.

POLYGONSTriangle-3 sidedQuadrilateral-4 sidedPentagon-5 sidedHexagon-6 sided

PolygonsHeptagon--7sidedOctagon--8 sidedNonagon--9 sidedDecagon--10 sided

PolygonsUndecagon--11 sidedDodecagon--12 sided**A regular polygon has equal sides.**

SQUAREALL SIDES ARE CONGRUENTOPPOSITE SIDES ARE PARALLEL. 4 RIGHT ANGLES

OPPOSITE SIDESARE CONGRUENTAND PARALLEL.4 RIGHT ANGLES.

OPPOSITE SIDES ARECONGRUENT AND PARALLEL

OPPOSITE SIDESARE PARALLEL.ALL SIDES ARE CONGRUENT.

Has 2 parallellines.