Transcript Technical Drawing

Drawing Basic Shapes
Triangles
•Equilateral triangles have all
angles equal to 60°
•All sides equal length.
•All equilateral triangles have 3
lines of symmetry.
Equilateral triangle
Right triangles (or right angled triangles)
have one right angle (equal to 90°).
Right triangles
Quadrilaterals
There are quite a few members of the
quadrilateral family.
• Squares have 4 equal sides and
4 right angles.
• They have 4 lines of symmetry.
• All squares belong to the
rectangle family.
• All squares belong to the
rhombus family.
• All squares are also
parallelograms.
Square
Quadrilaterals
Rectangle
• Rectangles have 4 sides and 4
right angles.
• They all have 2 lines of
symmetry (4 lines if they are
also a square!)
• All rectangles belong to the
parallelogram family.
Quadrilaterals
• Parallelograms have 2 pairs
of parallel sides.
• Some parallelograms have
lines of symmetry
(depending on whether they
are also squares, rectangles
or rhombuses), but most do
not.
Parallelogram
List of Geometrics Shapes 3D Shapes
• Cubes have 6 faces, 12 edges
and 8 vertices.
• All sides on a cube are equal
length.
• All faces are square in shape.
• A cube is a type of cuboid.
Cube
Cylinders
• Closed Cylinders have 3 faces,
2 edges and 0 vertices.
• Closed cylinders have 2
circular or elliptical faces and
one curved rectangular face.
Cylinder
Cones
• Cones have 2 faces, 1
edge and 1 apex (which
is described by some
mathematicians as a
vertex).
Cones
Area of geometric shapes
• Area of regular shape is calculated using standard
mathematical formula.
a) Triangle
– Use following formula to calculate area of triangle.
– Area = ½ base * height
b) Quadrilateral
– Area of quadrilateral = Length * breadth
c) Circle
– Area of circle A=π r * r ( r = Radius )
Geometric Lines to know
• Horizontal (straight)
• Vertical (straight)
• Oblique
• Ellipse (and circle)
• Curve
Methods of Drawing
• Sketching
• Drafting
• Computer Assisted Design (C.A.D.)