how do i construct a 80 degree angle with a compass...??
Draw a point, and a long straight line through it. Put the centre of the compass over the point, with north on the compass (or zero degrees) on the line. Then draw a second line out from the point at 80 degrees on the compass. You'll then have a 80 degree angle between the lines.
It's usually a trick that teachers decide to do on their pupils. A compass is what you use to find north and a pair of compasses is used to draw circles.
you must be knowing how to construct a 60 o angle, so I won't be writing down steps for that.
problem arises when we have to construct 20 o angle, so here are the steps :
- draw any line PQ. Mark a point O anywhere between P and Q on the line.
- With O as centre, and any suitable radius, draw an arc intersecting PQ at A and B .
- With B as centre, and he same radius, cut an arc C on previously drawn arc AB. This is the normal 60 o angle.
- With B and C as centres, cut arcs intersecting at L. This is the bisected 60o ie 30 o
- BUT DO NOT join L to O, instead join L to A. Angle LAQ is the required 20 o triangle.
- So now you can construct 60o on it . HOPE IT HELPS :D
This is your answer.
Hope that helps!!
1. Draw a line segment of any length
2. Consider any point A on the line segment draw a semi circle. And name the semicircle BC
3. Extend the line segment till left end of semicircle.
4. Draw an arc D from point C on line segment of same measurement that of semicircle.
5. Measure length BC.
6. Cut arcs from point B and D. That will give you a point of intersection.
7. Join the arc intersection with point A
8. Measure the angle this is 80?.