## Plans and Elevations

 7.2 Plans and Elevations
 Definition of Plan The orthogonal projection on a horizontal plane, which is seen from the top view.
 Definition of Elevation The orthogonal projection on a vertical plane, which is seen from either the side view or the front view.
 Drawing plan and elevations: Plan and elevations should be drawn to full scale. The drawings of a plan, a front elevation and a side elevation of an object can also be combined on a piece of paper which is divided into four quadrants. The position of the front elevation is at the top of the plan. The side elevation is drawn on the left side or the right side of the front elevation, depending on the viewing direction. Thick solid lines for visible sides, dashed lines for hidden sides and thin solid lines for construction lines.
 Example The following diagram shows a combination of a cuboid and a right prism with rectangle $$ABCD$$ on a horizontal plane. $$ABGHIF$$ is a uniform cross section of the object.  $$BH$$ and $$FI$$ are vertical. Draw to full scale: i) the plan of the object ii) the elevation of the object as viewed from $$X$$ iii) the elevation of the object as viewed from $$Y$$ The direction of side elevation (direction $$Y$$) is from left to right. Thus, the position of the side elevation is on the first quadrant.
 Synthesise plan and elevations of an object: Sketch the orthogonal projections using the measurements given. Mark the surfaces of the shape block. Project all the surfaces so that they meet. Sketch the object and label the vertices with letters. Complete the sketch by labeling the length of the sides.
 Example The following diagram shows the combination of a cuboid and a right prism. Sketch the three-dimensional shape of the object. The position of side elevation is in the first quadrant. So, the view of the side elevation is from left to right. This object contains an angle of $$60{^\circ}$$on a triangular surface. Thus, the angle must be built correctly.