Q17: A square pyramid of base side 40 mm and axis 60 mm is resting on its base on the H.P. with a side of base parallel to the V.P. Draw its sectional views and true shape of the section if it is cut by a section plane perpendicular to the V.P. bisecting the axis and is inclined at 450 to the H.P.
Steps of construction :
- The square pyramid is resting on the H.P. on its base, therefore its cross‐section is visible in the top view. Hence, a top view is drawn first.
Top view: Square of side 40 mm with on side parallel to the V.P.
2. The front view is drawn with the help of all the points from the top view projected vertically upwards. Front view: Square pyramid having base equal to a ‘ d ‘ and length of axis 60 mm long.
3. Section plane S1 S2 is drawn from the bisection point (midpoint) of the axis at an angle of 450 with the H.P., thus generating points 1′,2′,3′,4′ in the front view.
4. Sectional top view is drawn with the help of all the points from (1′ to 4′) front view projected downwards, thus generating points 1 to 4 in the top view.
5. True shape is drawn with the help of all the points from 1′ to 4′ and 1 to 4 from the sectional tope view.