Tri = 3 sides
Quad = 4 sides
Pent = 5 sides
Hex = 6 sides
TRI 3 SIDES SHAPES
Equilateral triangle - All angles equal to 60 degrees, all sides are equal, al equilateral triangles have 3 lines of symmetry.
Isosceles triangle - 2 angles equal, 2 sides have equal length, all isosceles triangles have a line symmetry or one line is reflected from the other.
Scalene triangle - No angles are qual, no sides are equal length.
Right angles triangle - 1 angle must have 90 degrees.
Obtuse Triangle - 1 angle must be greater than 90 degrees which are called an obtuse angle, the other 2 angles are less than 90 degrees which are called the acute angle.
Acute triangle - All angles must have less than 90 degrees.
QUAD 4 SIDED SHAPES:
Quadrilateral shapes must have:
- 4 sides and edges
- 4 vertices or corners
- Interior angles add up to 360 degrees
Rectangle - 4 sided shape, every angle is a right angle (90 degrees), opposite sides are parallel and equal of length.
Square - 4 sides are qual, every angle is a right angle (90 degrees), opposite sides are parallel.
Rhombus - 4 sided shape, all sides have equal length, opposite sides are parallel and opposite angles are equal.
An interesting fact in diagonal or dashed lines meets in the middle at a right angle.
Rhombus is also called a rhomb or a diamond.
Parallelogram - COntains opposite sides parallel and equal in length, Opposite angles are equal (2 angles are the same, and another 2 are the same).
Trapezoid - Has opposite sides parallel, quadrilateral no parallel sides.
Kite - Has two same length sides or each pair is made of two ewaul-length sides join up.
- two angles pairs are equal.
- the diagonals, shown as dashed lines above, meet at a right angle.
- 1 diagonal bisect (cut equally in half).
Polygons
There can be a regular polygon which all angles equal and all sides equal sides, but if they don't have this they will be an irregular polygon.
Pentagon - A regular pentagon contains five congruent sides, five same interior angles, five same exterior angles.
Exterior angles = 360/5 sides = 72 degrees. This is found because a regular polygon, going around a pentagon completes a full circle, this means the exterior angles are found by dividing 360 degrees by the numbers of the sides.
Irregular pentagons - Convex no internal angles can be more than 180 degrees, concave one interior angle that is greater than 180 degrees.
Hex- 6 sided shapes - hexagon
Regular / irregular
When all angles are equal and all sides are equal it is regular, otherwise, it is irregular.
A concave/convex
A convex hexagon no angles pointed inwards, no internal angles can be more than 180 degrees.
