## VISUALIZING SOLID SHAPES- ESSENTIAL POINTS

• The circle, the square, the rectangle, the quadrilateral and the triangle are examples of plane figures.
• The cube, the cuboid, the sphere, the cylinder, the cone and the pyramid are examples of solid shapes.
• Plane figures are of two-dimensions (2-D) and the solid shapes are of three-dimensions (3- D).
• Vertices are the corners of solid shapes.
• Edges are the line segments of its skeleton
• Faces are its flat surfaces.
• A net is a skeleton-outline of a solid that can be folded to make it. The same solid can have several types of nets.
• 2-D representation of 3-D objects is used to draw solid objects on flat surface.
• Two types of sketches of a solid are possible:
• An oblique sketch does not have proportional lengths. Still it conveys all important aspects of the appearance of the solid.
• An isometric sketch is drawn on an isometric dot paper and measurements of solid are kept proportional.
• Visualizing solid shapes is a very useful skill. You should be able to see ‘hidden’ parts of the solid shape.
• Different sections of a solid can be viewed in many ways:
• View by cutting or slicing the shape and observing the cross section of object.
• Observing a 2-D reflection of a 3-D shape.
• Observing from different angles; the front-view, the side-view and the top view can provide a lot of information about the shape observed.
• A line is straight and extends in both directions forever.
• A plane is a flat surface that extends in all directions.
• A line segment is the part of line between two points.
• A ray starts from a fixed point and goes to any distance to the other direction of the starting point.