Geometry

Square: Four equal sides and four equal angles which are parallel.

Triangle: A three sided shape, all interior angles = 180

Decagon: 10 sided sides, 10 corners connecting the shape

Rectangle: a 4 sided shape with two longer sides apposing and 2 shorter
apposing sides

Lozenge: often referred to as a diamond

Hexagon: a 6 sided shape, the total of the internal angles = 720

Rhomboids:a parallelogram with adjacent sides are of un equal length and are not right angled.

Trapezium: a quadrilateral with two sides parallel

Octagon: an eight sided shape, with eight interior obtuse angles

Icosagon: In geometry, an icosagon or 20-gon is a twenty-sided polygon. The sum of any icosagon's interior angles is 3240 degrees 
 Tridecagon: In geometry, a tridecagon or triskaidecagon or 13-gon is a thirteen-sided polygon.

Why Triangles Are Important In Building And Construction?

Why Triangles Are Important In Building And Construction?

Triangles are important Because you can use different materials to create tension and/or compression. When you want to build a house they put triangles in the roof to make the whole building stronger, because if you were to apply force on a house with a square roof it would cause the material to collapse whereas when force is applied to a triangle it will
One create compression 
And Two create Tension along the bottom side.

If you Were to have a failure there are 5 Types.
1. Compression
2. Tension
3. Bending
4. Shear
5. Torsion

1. Compression is when two forces are pushing against each other
2. Tension is two forces pulling against each other
3. Bending is where a force in the middle of say a piece of timber is acting against two forces on each end of the timber, as shown above.
4. Shear is where two forces, one at each end are acting