Answers

2014-10-11T13:32:33+05:30
1. With O as center , draw an arc of any radius to cut OA at B
2. With B as center and radius as taked in step 1, draw the arc to cut the previous arc at C
3. Again with C as center and with the same radius, draw one more arc to cut the frist arc at C
4.With C and D as centers , draw  two arcs of equal radius to cut each other at E
5. join OE . Then, AOE=90 
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2014-10-11T13:51:37+05:30
Let BC be any line segment .
With B as center and any radius <BC , draw an arc which cuts BC at D.
With D as center and with the same radius , draw another arc which cuts the previous arc at E.
With E as center as with the same radius, draw another arc which cuts the 1st arc at F.
With E and F as centers and with any radius >1/2 EF, draw 2 arcs which cut each other at A(Both arcs should be drawn with equal radii).
Join A and B , then Angle ABC=90* is the required angle.
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