Question

using a protacter draw an 80 degree angle and using ruler and compass make a copy of angle, also, make a xopt of the suppliment of the angle​

Answer 1

Steps of construction :

1. Draw a ray OA.

2. With the help of a protractor , construction ∠ BOA = 80

∘

3. Taking O as center and any suitable radius , draw an arc to intersect rays OA and OB at points P and Q respectively .

4. Take radius more than half the radius OP.With this radius make an arc from point P and Q which will intersect at X . By joining O and X we get bisector of ∠AOB .

Let ray OC be the bisector of ∠ BOA , then ∠ COA =

2

1

∠ BOA =

2

1

×80

∘

=40

∘

.

5. With Q as center and radius equal to PQ , draw an arc to cut the extended arc PQ at R . Join OR and produce it to form ray OD , then ∠ DOA = 2∠ BOA = 2×80

∘

=160

∘

.

6. Bisect ∠ DOB as done in step 4. Let OE be the bisector of ∠ DOB is then

∠ EOA = ∠ EOB + ∠ BOA =

2

1

∠ DOB + ∠ BOA =

2

1

(80)

∘

+80

∘

=40

∘

+80

∘

=120

∘