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CHAPTER 3, , PROJECTIONS OF PLANE SURFACES, , * Problem 1 An equilateral triangular lamina of 25mm side lies with one of its edges on HP such that the surface of, the lamina is inclined to HP at 60°. The edge on which it rests is inclined to VP at 60°. Draw the projections., Solution, , , , , , , , Problem 2 An equilateral triangular lamia of 25mm side lies on one of its sides on HP. The lamina makes 45° with, * HP and one of its medians i is inclined at 40° to VP. Draw its projections., , , , , , , , , , , , , , , , , , , , , , , , Solution, c e, Pe,, , vP bia’) c bia’) / 8, xX i Y, , HP, , a a _Locus of D, a di c d c, Hi b b, i 53, , Scanned with CamScanner
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Problem 3 A triangular lamina of 25mm side, , rests on one of its corners on VP such that the median passing through, the corner on which it rests is inclined at 30° s, , to HP and 45° to VP. Draw its projections,, , , , , , , , , , , , Solution _, (, /, z ce, d \d1" Locus of D, % oO, %, VP, x Le) *, HP, ra, , Problem 4 A triangular plane figure of sides 25mm, -the lamina makes an angle of 60° with HP. If the side oj, of 30° with VP, draw the top and front views, , is resting on HP with one of its corners, such that the surface of, , posite to the corner on which the lamina rests makes an angle, in this position. 7, , , , , , , , , , , , , , Solution, be) ¢ b, vey |, x a Pe) af Cort vp, ch 3 be, 7 e IS, a, , sal al, , bb, , ae a ;, Problem 5 Atriangular plane lamina of Sides 25mm is re, side opposite to the comer on which it rests is 15mm, , front views in this position. Also determine the inclin, Solution, , sting on HP with one of its corners touching it, such that the, above HP and makes an angle of 30° with VP. Draw the top and, lation of the famina to the reference plane., , bi(c) c b, (TF, , , , , , vP \, , , , HP, , , , , , 54, , , , Scanned with CamScanner
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|, |, , ¢ Problem 6 A30°-60° setsquare of 60mm longest,side is so kept such that the longest side is in HP, making an angle, of 30° with VP. The set square itself is inclined at 45° to HP. Draw the projections of the setsquare. *, Solution, , , , , , , , , , , , , , , , , , , , , , Cc ec, ie, x bay 9 "YS wR y, Jai HP, al\: al, pO od, 7, © ai, fg, , WY, 600. ic, NN ¢, tt 4, b, , /, Roe”, © Problem 7 An isosceles triangular plate of negligible thickness has base 25mm long and altitude 35mm. It is so, , placed on HP such that in the front view itis seen as an equilateral triangle of 25mm sides with the side that is parallel, , to VPs inclined at 45° to HP. Draw its top and front views. Also determine the inclination of the plate with the reference, plane, ., , Solution, , , , , , , , , , , , , , , , 2, 2, a, », °, , a(c) b, , , , 55, , 1, , Scanned with CamScanner
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on which it rests makes 45° to VP. Draw its projections., , 2, ‘A roblem 8 Asquare lamina of 40mm side rests on one of its sides on HP. The lamina makes 30° to HP and the side, , , , , , , , , , , , , , , , , , , , to VP. Draw its projections., , , , , , i Solution, / (eyo bY é, ge a @) (yb a) 2 dt ¥, i HP | r B,, | is 5,, dq" /\e 3 q \, p : d, 2 VY, g y, G /, f., a b al Ib s 4, b . :, , yom ., Jt Problem 9 Asquare plate of abmm sides rests on HP such that one of the diagonals is inclined at 30°to HP and 45°, , , , , , , , , , , , , , , , , , , , , , , , Solution, ce ic, » a ie, 7 b, b 2 | ., . : 8 a, vp a : : , [, ’ ge a | | “| y, HP }, d id | ‘, |, aft _ \ / b, e a SS, ‘ , at a Locus of A, |, °, | %, x b B, |, |, |, |, |, q&, 56, :, , , , , , - Scanned with CamScanner
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ptatn 10 Asquare lamia ABCD. of 40mm side rests.on comet such that the diagonal AC appears to be at 45°to ,, VP. The two sides BC and 6D containing the corner C make equal inclinations with HP. The surface of the lamina makes, 30° with HP. Draw its top and front views., , Solution, , , , , , , , , , , , , , , , , , , , vd), a bd) c a 8, t, a 5 } ld, a i J, ; a, | ‘, [2, b, , , , ,, wot be Lourrol, A ’, , i C-Froblem 11 The top view of a square lamia of side 30mmis a rectangle of sides 30mm x 20mm with the longer side, , | » of the rectangle being parallel to both HP and VP. Draw the top and front views of the square lamina. What is the, inclination of the surface of the:lamina with HP:and VP?, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , i | Solution ., 7 Yde Mew, RPP wedtvod, Lsv, |, ! ve) c y, |, Dy . fg, | sia n/ ®, | % vP_ ad’) bc) ad’ i a a "ya" ¥, HP | a], . i e¥, d ?, c, TW c “T a d, J ©, Gh 8, bo ah, a b al 20 [>, vt, oy 57, , , , Scanned with CamScanner
