Page 121 - CITS - ED - Mechanical

ENGINEERING DRAWING - CITS

Exercise 7.10

Draw the development of the lateral surface of a square pyramid of base 40 mm and vertical height 60 mm. (Fig 10)
• Draw the plan and elevation of the pyramid.
• With O as centre in top view and ob as radius, draw an arc to meet the axis at 1.
• Project the point 1 to front view to meet the base line at 1'.
• Join O'1' which is the true slant length of the pyramid.
• With `O 'as centre and true length as radius draw an arc and set off the sides of the pyramid on the arc at
1
A,B,C,D & A.
• Join O A, B, C, D, AO which is the required development.
1 1

Fig 10

Exercise 7.11
Draw the development of the lateral surface of a hexagonal pyramid of side 20 mm and height 60 mm. (Fig 11)

• Draw the top view and front elevation of the hexagonal pyramid.
• With `O ' as centre and slant length as radius draw an arc.
1
• Set off six equal sides (40 mm) on the arc at A,B,C,D,E,F & A.
• Join O , A,B,C,D,E,F and A O . Complete the lateral surface development of the pyramid.
1 1

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CITS : Engineering Drawing (Mechanical) - Exercise 7