This document provides step-by-step instructions for drawing the isometric view of a truncated pentagonal pyramid. The pyramid has a base side of 30mm and axis height of 65mm. It is cut by a plane passing through a point 30mm from the apex and inclined at 30 degrees to the horizontal plane. The instructions first show how to draw the front and top views of the full pyramid. It then explains how to mark the cutting points on these views and plot them on the isometric axes to draw the remaining portion of the pyramid after cutting.

1. Isometric View of a Truncated
Pentagonal Pyramid
Drawing Steps By:
SUBIN B MARKOSE
Assistant Professor

2. Question
• A pentagonal pyramid of base side 30 mm and axis
height 65 mm is resting on HP on its base with a
side of base perpendicular to VP. It is cut by a plane
inclined at 30 degrees to HP and perpendicular to
VP, passing through a point on axis at 30 mm from
the apex. Draw the isometric view of the remaining
portion of the pyramid.

3. Step 1
• Draw the front and top view of the pyramid in the
specified position.
• Mark the dimensions.
• Name the solid correctly.

5. Step 2
• Mark the point on axis through which cutting plane
is passing.
• Mark the dimension.
• No separate name is given to that point.

7. Step 3
• Draw the cutting plane inclined at 30 degrees to HP.
• The cutting plane cuts the edges of the pyramid at
the points a,b,c,d & e.
• Mark them clearly on front and top view.

9. Step 4
• Join the cutting points on top view and shade the
region.
• Now sectional top view is complete.

11. Step 5
• Enclose the top view inside a box.
• Name the box as 1-2-3-4.
• Draw the isometric axes and plot the point '1'.
• Similarly plot all other points of the box 2,3 & 4 on
the isometric axes and complete the box.

15. Step 6
• The base of the pyramid is a pentagon.
• Plot all the corners of the pentagon on the
isometric view.
• This is done by plotting the points from the top
view and marking them correctly on to the
isometric axes.
• Distance of corners of pentagon should be taken
correctly from top view and plot them on the
correct edges.

17. Step 7
• Now we are going to plot the cutting points a,b,c,d
& e on the isometric view.
• Let us start with point 'a'.
• Focus on point '5 ' on top view.
• Point '5' is obtained by drawing a horizontal line
through point 'a'.
• Point '5' is on edge 4-1.

19. Step 8
• Plot point '5' on to isometric axis 4-1.

21. Step 9
• Draw a line through point '5' parallel to edge 1-2 .
• Mark the distance 5-a from top view on the
parallel line as shown.
• Please look carefully as construction lines are
drawn very lightly.

24. Step 10
• We are going to plot point 'a' on the isometric
view.
• Point 'a' is at a particular height above XY line
which can be taken from front view.
• Measure the height of point 'a' from XY line and
plot it on isometric view.
• Study the coming slides thoroughly and
draw.

27. Step 11
• Repeat the same steps for plotting other points
b,c,d,& e.
• Draw a horizontal line through point 'b' and
mark point '6' on top view.
• From top view, plot 6 onto isometric view.

30. Step 12
• Point 'b' is also at the same height as that of point
'a' which can be measured from front view.
• Plot 'b' at the height as shown.
• It is drawn very lightly so look carefully.

32. Step 13
• For plotting points 'c & 'd', draw two horizontal
lines and mark points '7' & '8'.
• Repeat the same steps we used to plot the points
'a' & 'b'.
• Follow the images thoroughly.

35. Step 14
• Now the last point 'e' has to be plotted.
• It is much easier and refer the slides for clarity.
• Repeating same steps as before.

38. Step 15
• Now we have plotted all the cutting points on the
isometric view.
• Join them to get the top face of the pyramid.

40. Step 16
• Join the edges of the pyramid looking at the front
and top views.
• Highlight the truncated pyramid as shown.

43. Comments
• Feel free to rectify doubts.
• Draw lightly.
• Here you have to take measurements from both
top and front views to complete the isometric view.
• Naming the cutting points is very important.
• Draw very carefully.

44. • End of presentation...