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Ex 11.1, 4 (i) - Ex 11.1

Ex 11.1, 4 (i) - Chapter 11 Class 9 Constructions - Part 2
Ex 11.1, 4 (i) - Chapter 11 Class 9 Constructions - Part 3
Ex 11.1, 4 (i) - Chapter 11 Class 9 Constructions - Part 4
Ex 11.1, 4 (i) - Chapter 11 Class 9 Constructions - Part 5

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Ex 11.1, 4 Construct the following angles and verify by measuring them by a Protractor : 75° 75° = 60° + 15° 75° = 60° + (𝟑𝟎°)/𝟐 So, to we make 75° , we make 60° and then bisector of 30° Steps of construction Draw a ray OA. Taking O as center and any radius, draw an arc cutting OA at B. 3. Now, with B as center and same radius as before, draw an arc intersecting the previously drawn arc at point C. 4. Now, with C as center, and same radius, draw another arc intersecting the previously drawn arc at point D 5. Draw ray OE passing through C and ray OF passing through D Thus, ∠ AOE = 60° and ∠ EOF = 60° 6. Taking C and D as center , with radius more than 1/2CD, draw arcs intersecting at P. 7. Join OP Thus, ∠ AOE = 60° and ∠ EOF = 60° 6. Taking C and D as center , with radius more than 1/2CD, draw arcs intersecting at P. 7. Join OP Thus, ∠ EOP = 30° Now, we bisect ∠ EOP i.e. (30°)/2 = 15° 7. Mark point Q where OP intersects the arc 8. Taking Q and C as center , with radius more than 1/2QC, draw arcs intersecting at R. 9. Join OR Thus, ∠ AOR = 75° On measuring the ∠ AOR by protractor, we find that ∠ AOR = 75° Thus, the construction is verified

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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 12 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.