Question 9 - Constructing a copy of a given angle - Practical Geometry
Last updated at April 16, 2024 by Teachoo
Practical Geometry
Concept wise
- Basics
- Construction of a circle when its radius is known
- Construction of a line segment of a given length
- Constructing a copy of a given line segment
- Perpendicular to a line through a point on it
- Perpendicular to a line through a point not on it
- Perpendicular bisector of a line segment
- Constructing an angle using protractor
- Bisector of an angle
- Constructing angles using compass
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Constructing a copy of a given angle
Transcript
Question 9 Draw an angle of 40 °. Copy its supplementary angle. Let’s first draw a rough figure So, lets first draw 40° We follow these steps Draw a line with point O & A on it 2. Place center of protractor on point O, and coincide line OA and Protractor line Mark point B on 40° Join OB ∴ ∠ AOB = 40° Now, we need to make a copy of its supplement. Let’s follow these steps Draw a ray OP 2. In our ∠ AOB, From point O, draw an arc of any radius on the supplement of 40°, intersecting the sides at D & E 3. Using compass opened the same length, draw an arc with point O as the center, cutting OP at Q 4. Now, back to our angle ∠ BOA. Open compass to length DE 5. Keeping the same radius, Put pointed end of compass on point Q, and draw an arc. The point where it cuts previous arc is point R. 6. Join OR Thus, ∠ ROQ is the copy of ∠ BOA = 70° 6. Join OR Thus, ∠ ROQ is the copy of ∠ BOA = 70°
