Calendar: 1865-1866 Page 545

APPLIED SCIENCES 547 VI Practical conutri An isosceles triangle ABC has its sides inches long and its base Α Β 855 inches the corner is Β 175 3-5 inches above the paper Draw its plan be The points of this triangle are three of those of regular pentagon Β being one side complete the plan of this pentagon and state the heights above the paper of the two remaining points and Έ Six indefinite lines are parallel and equidistant l-5 inches from each other and all at that distance from seventh deter- mine the plans of these lines when they are inclined to the paper 60 and show an elevation of them If these six lines are the edges of right prism the seventh being the axis determine the section of it by the plane of the paper and also that by another plane inclined at 70 but in any direction at pleasure The true form of this section to be deter- mined Draw the plan and elevation of regular octahedron of inches edge in any position at pleasure provided no edge ii either horizontal or vertical triangle has its sides 2" ac 3" and 3"75 the point Β is 1" and C3" inches above the paper at what height above the paper must the point be so that the angle CΒ may be right angle or so that Β AC may be right angle Determine three planes mutually at right angles two of them being inclined at 50 and 70 to the paper Three spheres of "1 and 2" inches radii lie on the paper each sphere touching the other two show them in plan and determine second plane touching all three marking on each sphere the point of contact No student is to construct more than five of tl ese questions Μ Μ