Projection of Planes
Sample Problem 1: Rectangle 30mm and 50mm sides is resting on HP on one small side which is 30o inclined to VP, while the surface of the plane makes 45o inclination with HP. Draw it’s projections.
Steps for projection of planes:
Step 1. Draw a rectangle abcd of sides 30mm & 50mm, which is parallel to HP. This is the top view of the rectangle. Now, draw the projection of it’s sides above the XY axis. This is the front view of the rectangle i.e. a’b’c’d’.Step 2. Now, the front view a’b’c’d’ of the rectangle makes 45o inclination to the HP. Draw it’s projection below XY axis, which gives the top view a1b1c1d1.Step 3. Now, make 30o inclination of one of the small side of rectangle a1b1c1d1. to the VP. Finally draw the points a1‘b1‘c1‘d1‘ as shown above .
Step 1. Draw a rectangle abcd of sides 30mm & 50mm, which is parallel to HP. This is the top view of the rectangle. Now, draw the projection of it’s sides above the XY axis. This is the front view of the rectangle i.e. a’b’c’d’.Step 2. Now, the front view a’b’c’d’ of the rectangle makes 45o inclination to the HP. Draw it’s projection below XY axis, which gives the top view a1b1c1d1.Step 3. Now, make 30o inclination of one of the small side of rectangle a1b1c1d1. to the VP. Finally draw the points a1‘b1‘c1‘d1‘ as shown above .
Problem 2 : A circle of 50 mm diameter is resting on Hp on end A of it’s diameter AC which is 30o inclined to Hp while it’s Tv is 45o inclined to Vp. Draw it’s projections.
Steps for projection of planes:
Step 1.. Firstly, draw a circle of 25 mm radius(or 50 mm diameter) parallel to HP.
This is the top view of the circle. Name it abcd as shown in figure & draw it’s projection above the XY axis, which is the front view of the circle i.e. a’b’d’c’.
Step 2.. Now, the front view a’b’d’c’ of the circle makes 30o inclination to the
HP. Draw it’s projection below XY axis, which gives the top view a1b1c1d1.
Step 3. Now, make 45o inclination of the diagonal a1c1 to the VP. Finally draw the points a1‘b1‘c1‘d1‘ as shown above .