6. The top view of 80 mm line AB measures 60 mm. Its end A is 50 mm in
front of the VP and 15 mm above the HP. The point B is 20 mm in front of VP
and is above HP. Draw its projections and find its true inclinations with HP
and VP
A is in front of VP and above HP and B is in front of VP and above HP: Line in first quadrant
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x y
a’
a
Locus of bb1b
Elevation length
b’b1’
Locus of b’
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7. A fan is hanging in the center of a room 6 m X 5 m X 4 m height. The center of the fan is 0.6 m below the ceiling. Determine graphically the distance the shortest distance of the fan from one of the corners of the floor
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8. The end A of line AB is 10 mm above the HP and 30 mm in front of the VP. The end B is 50 mm below the HP and 15 mm behind the VP. The length of the line is 80 mm. Draw the projection and locate its traces
a’
a
x y
Locus of b’b1’
Locus of b
b
b’
h’ v
HTVT
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3b. Draw the projections of a line AB of 50 mm length having its end A in
the HP and the end B 30mm behind the VP. The line is located in the second
quadrant and is inclined at 20o to the HP and 35o to the VP.
End A in the HP: elevation of point A, a’ on XYLine in second quadrant: Elevation and Plan lies above XY
True length and true inclination with HP is given: Plan length can be find out
True length and true inclination with VP is given: Elevation length can be find out
a’
x y
b1’
Locus of b’
Plan length
True length
Elevation length
b’
Locus of bb
a
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3c. Draw the projections of a line AB of 50 mm length having its end A in
the HP and the end B 30mm behind the VP. The line is located in the second
quadrant and is inclined at 20o to the HP and 35o to the VP. The end point
A is nearer to VP when compared to point B
a’
x
b1’
Plan length
b’
Locus of bb
a
a’x
b1’
Plan length
b’
Locus of bb
a
The end point B nearer to VP when compared to point A
The end point A is nearer to VP when compared to point B
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1a. A 90 mm long line AB is inclined at 20 to the HP. The end A is 12 mm above the HP and the end B is 30 mm in front of the VP. Draw projections of the line if its front view measures 76 mm. Locates traces (a) Assume end point A is in the first quadrant (B) Assume end point A is in the third quadrant
x y
a’
b’1
Locus of b’
b’
Locus of b
b
a
Plan length
a
A is in first quadrant
A is in third quadrant
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Auxiliary Plane
• Auxiliary Plane: Any plane perpendicular to an RP and inclined to the other RP
• In practice1. Auxiliary inclined plane (AIP)
• Inclined to HP and perpendicular to VP
2. Auxiliary vertical plane (AVP)• Inclined to VP and perpendicular to HP
• AIP is seen as line in FV• AVP is seen as line in TV• Auxiliary plane projection method provides quick and
accurate solutions to many projection problems– Especially in projections of planes and solids.
XY10
24
55
50
X1Y1
24
VT
50
TL
X2Y2
HT
10
55
Φ
θ
TL
Auxiliary Projection MethodTrue LengthTrue InclinationTraces of a line
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Common Questions•A 90mm long line PQ is inclined at 45⁰ to the H.P. and 30⁰ to the V.P. The ends P is 20mm above the H.P. and in the V.P. Draw the Projections and locate the traces.
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p’
p
q1’
q
q’
q1
•A straight line PQ has the end P at 15mm above the H.P. and 60mm infront of the V.P. and the end Q is 45mm above the H.P. and 10mm infront of the V.P. If the end projections are 60mm apart, draw the projections of the line. Determine its true length and true inclination with the principal planes.
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