A right pyramid, whose altitude is 3 inches, has for its base a Ij-inch square, 

 two opposite sides of which are parallel to the vertical plane. The apex 

 is 1 inch behind the vertical plane and 2 inch below the horizontal plane. 

 The axis is parallel to the vertical plane and inclined at an angle of 60 degrees 

 to the horizontal. 



a) Draw the horizontal and vertical projections of the pyramid. 



b) Find the true size and shape of the section cut from the pyramid by a 



plane parallel to the vertical plane and f inch behind it. 



Description. — The material of the rack shown above is all f inch thick and the 

 rod is f inch in diameter. The board is 15 inches long and 4§ inches wide. 

 Each bracket is made from a piece 3 inches long and 2 inches wide, by cut- 

 ting off the two corners at 45 degrees, as shown. The hole is in the center 

 of the bracket. Each bracket is screwed to the board symmetrically, the 

 nearest edge being § inch from the end of the board. 



Problem. — Make a working drawing of the rack shown above. Include a 

 top view, a front view, and an end view, using a scale of \ inch to 1 inch 

 (j actual size). Put on all necessary dimensions. Using some simple 

 single-stroke free-hand lettering, print carefully a title (Towel Rack), and 

 such brief notes as will inform the workman what materials are to be used, 

 how they are to be fastened together, and what finish you would suggest for 

 the surfaces. 



6. A right cylinder, Ij inches in diameter, whose axis is 2 inches long and 

 vertical, stands at the center of the upper face of a block \h inches wide, 

 1| inches deep, and 2 inches high. The cylinder is cut by a plane which 

 passes through its axis parallel to the front face of the block and the half 

 of the cylinder in front of the plane is removed. INIake an isometric draw- 

 ing of the block and the remaining half of the cylinder. 



