Page 22 - ENGINEERING DRAWING
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b) Construct an acute angle of 30 o
Steps of construction:
i. Draw the line Ol
ii. Place the point of the compass at O and draw an arc that passes through AB.
iii. Place the point of the compass at A and draw an arc that passes through O. Let
this arc cut the arc drawn in Step 2 at B.
iv. Join 0 to B. The angle AOB is 60 o.
o
We know that: ½ of 60 = 30 o
v. With the point 0f the compass still at A, draw an arc near C as shown.
vi. With the point of the compass at B, draw an arc to cut the arc drawn
in Step v at C.
o
vii. Join O to C. The angle ∠AOC is 30 .
c) Construct an obtuse angle of 120 o
