{"id":2243,"date":"2023-10-02T11:28:41","date_gmt":"2023-10-02T11:28:41","guid":{"rendered":"http:\/\/localhost\/ecole9ja\/?p=2243"},"modified":"2023-10-02T11:34:55","modified_gmt":"2023-10-02T11:34:55","slug":"week-2-ss1-second-term-technical-drawing-notes","status":"publish","type":"post","link":"https:\/\/ecolebooks.com\/nigeria\/posts\/week-2-ss1-second-term-technical-drawing-notes\/","title":{"rendered":"Week 2 – SS1 Second Term Technical Drawing Notes"},"content":{"rendered":"

\u00a0
\n\u00a0WEEK TWO DATE:\u2026\u2026\u2026\u2026\u2026\u2026
\n<\/strong>Escribed circles
\n<\/strong>
\n\u00a0Content:
\n<\/strong>(i) Escribed circles.
\n(ii) Drawing of circles to touch some given points.<\/p>\n

\u00a0Escribed circles.
\n<\/strong>\"\"\/Example 1 To escribe a circle on a given triangle.<\/em><\/strong>
\n\t\t\u00a0\u00a0\u00a0\u00a0
\nMethod:<\/strong>
\n\t\t(i) Draw the given triangle ABC.
\n(ii) Extend AC to D and AB to E.
\n(iii) Bisect the two exterior angles <DCB and <EBC
\nwhose bisectors intersect at point O.
\n(vi) Draw a line from O perpendicular to any of the sides.
\n(v) With O as centre and radius OQ, escribe the circle. <\/p>\n

\u00a0
\n\u00a0Example 2 To escribecircles on a given polygon.\"\"\/<\/em><\/strong><\/p>\n

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\n\u00a0
\n\u00a0
\n\u00a0Method:
\n<\/strong>(i) Draw the given polygon and join opposite corners as shown above.
\n(ii) Bisect external angles P23 and S32 whose bisectors meet at point O, the centre of the circle.
\n(iii)Drop a perpendicular, OD to side 2-3. This is the radius of the circle.
\n(iv)With O as centre and radius OD, draw a circle. Repeat the above procedure for each side and circle. <\/p>\n

\u00a0Evaluation Questions
\n<\/strong>1. Escribe a circle on a triangle of sides AB = 55mm, AC = 60mm and BC = 50mm.
\n2 . A regular hexagon has its sides 50mm long. Draw the hexagon and describe circles about it.<\/p>\n

\u00a0
\n\u00a0
\n\u00a0
\n\u00a0Drawing of circles to pass through given points.
\n<\/strong>
\n\u00a0\"\"\/Example 1To draw a circle to pass through a given point and touch a line at a given point<\/em><\/strong><\/p>\n

\u00a0
\n\u00a0
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\n\u00a0
\n\u00a0
\n\u00a0Method:
\n<\/strong>(i) Locate the given point A and the given point R on the given line PQ.
\n(ii) Join the two given points ie, RA.
\n(iii)Erect a perpendicular at the point R on the given line.
\n(iv) Draw a line AO from point A<\/strong> to meet the perpendicular RS at point O; such that angle RAO is equal to
\nangle ORA. Point O is the centre of the circle that will pass through the given points.<\/p>\n

\u00a0
\n\u00a0Example 2To draw a circle to pass through two given points and touch a given line.
\n<\/em><\/strong>\"\"\/<\/p>\n

\u00a0
\n\u00a0Method:
\n<\/strong>(i) Locate the two given points F and G and draw the
\ngiven line CD.
\n(ii) Draw a line to connect F and G and extend the line.
\n(iii) Extend the line CD to meet FG extended at point E.
\n(iv) Mark off EH equal to EG.
\n(v) Construct a semicircle on line FH.
\n(vi) Draw a line perpendicular to AH at point E to touch the semicircle at point K.
\n(vii) Mark off EP equal to EK.
\n(viii) Draw a line perpendicular to CD at point P and this line intersects the
\nbisector of FG at point O, thecentre of the circle required.
\n(ix) With O as centre and radius OP, draw the circle.<\/p>\n

\u00a0
\n\u00a0Evaluation Questions
\n<\/strong>\"\"\/<\/p>\n

\u00a0
\n\u00a0
\n\u00a0
\n\u00a0
\n\u00a0
\n\u00a0
\n\u00a01. Draw a line AB of length 80mm and locate a point Q on it which is 20mm from end B. Draw a circle to
\ntouch points P which is at a suitably chosen distance and Q.<\/p>\n

\u00a0
\n\u00a0
\n\u00a02. Draw a circle to pass through points P and B and also touch line AC as shown below. Choose suitable
\n\"\"\/positions for points P and B and line AC. <\/p>\n

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\n\u00a0
\n\u00a0\u00a0\u00a0\u00a0\u00a0
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\n\u00a0
\n\u00a0General evaluation\/ revisional questions
\n<\/strong><\/p>\n

    \n
  1. Draw an equilateral triangle of side 60mm and inscribe three equal circles with two circles touching each side.\n<\/li>\n
  2. \n
    \"\"\/ Choose any convenient point S and draw a tangent to the circle shown below.\n<\/div>\n

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    \n\u00a0
    \n\u00a0
    \n\u00a0
    \n\u00a0
    \n\u00a0
    \n\u00a0<\/li>\n<\/ol>\n

    3. Determine graphically the circumference of a circle, diameter 35mm.
    \n4. Construct a line of approximate length to the given arc shown below.
    \n\"\"\/<\/p>\n

    \u00a0
    \n\u00a0
    \n\u00a0Reading assignment
    \n<\/strong>Technical drawing by JN Green. Pages 21, 73-75.
    \n\t\t\t\t<\/strong>
    \n\u00a0Weekend Assignment<\/strong>
    \n\t\tObjective<\/strong>
    \n\t\t1. Which of the following is correct in escribing a circle on a triangle? A. Bisect two internal angles.
    \n\"\"\/ B. Bisect two sides of the triangle. C. Bisect two external angles. D. Bisect three sides of the triangle.<\/p>\n

    \u00a0
    \n\u00a0
    \n\u00a0
    \n\u00a0
    \n\u00a0
    \n\u00a02. The radius of the circle drawn in the diagram above is represented by line A. CD. B. OB. C. OQ.
    \n D. QD.
    \n\"\"\/3. The figure below shows the construction of a\/an A. circumscribed circle. B. circumscribed triangle.
    \nC. escribed triangle. D. escribed circle.<\/p>\n

    \u00a0
    \n\u00a0
    \n\u00a04. Which of the following is not a procedure for describing a circle round a polygon? A. Bisect two external
    \nangles. B. Bisect two sides. C. Draw a line from the determined centre, parallel to one side.
    \n D. Draw a line from the determined centre, perpendicular to one side.<\/p>\n

    \u00a0\"\"\/5.AB is the diameter of the circle shown below. What type of triangle is ABC? A. Scalene. B. Right
    \nangled. C. Oblique. D. Isosceles.
    \n\t\t\t\t<\/strong>
    \n\u00a0
    \n\u00a0
    \n\u00a0
    \n\u00a0
    \n\u00a0
    \n\u00a0
    \n\u00a0Theory
    \n<\/strong>1 . A regular hexagon has its sides 50mm long. Draw the hexagon and describe circles about it.
    \n\"\"\/<\/p>\n

    \u00a0
    \n\u00a0
    \n\u00a0
    \n\u00a0
    \n\u00a02. Draw a line AB of length 80mm and locate a point Q on it which is 20mm from end B. Draw a circle to
    \ntouch points P which is at a suitably chosen distance and Q.<\/p>\n","protected":false},"excerpt":{"rendered":"

    \u00a0 \u00a0WEEK TWO DATE:\u2026\u2026\u2026\u2026\u2026\u2026 Escribed circles \u00a0Content: (i) Escribed circles. (ii) Drawing of circles to…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1,192],"tags":[],"class_list":["post-2243","post","type-post","status-publish","format-standard","hentry","category-posts","category-second-term-ss1-technical-drawing"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts\/2243","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/comments?post=2243"}],"version-history":[{"count":1,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts\/2243\/revisions"}],"predecessor-version":[{"id":2244,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/posts\/2243\/revisions\/2244"}],"wp:attachment":[{"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/media?parent=2243"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/categories?post=2243"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ecolebooks.com\/nigeria\/wp-json\/wp\/v2\/tags?post=2243"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}