Question

Using a ruler and compasses, construct the following angles:
(a) 120°
(b) 67½
(C) 105​

Answer 1

)

1. Draw a ray OX.

2. Cut an arc from O, cut another arc of same length as OA, which intersects at B.

3. Cut two arcs from A and B which intersects at C.

4. Join O−C. ∠COA is 30

∘

.

2)

1. Draw a ray OX.

2. Cut an arc from O, cut 2 another arcs of same length as OA, which intersects as B and F.

3. Cut two arcs from B and F which intersects at C. (∠COX=90 deg)

4. In the similar way, bisect ∠COX to get DOX which is 45 deg angle and then again bisect ∠DOX to get to get EOX .

6. Join O−E. ∠EOA is 22.5

∘

.

3)

1. Draw a ray OX.

2. Cut an arc from O, cut another arc of same length as OA, which intersects at B.

3. Cut two arcs from B and A which intersects at C. (∠COX=30 deg)

4. In the similar way, bisect ∠COX to get DOX.

6. Join O−D. ∠DOA is 15

∘

.

solution