C6. The "Circumcircular Arc" tool
Draw the horseshoe arch
The horseshoe arch surpasses a semicircle. You have to distinguish between the centre of the arch and the centre of the starting line.
1st. Activate the "Circumcircular Arc" tool 
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2nd. Click on the beginning of the arc located on the left. It will be the point "A".
3rd. Click on the top of the middle arch. It will be the point "B".
4th. Click on the end of the arch located on the right. It will be the point "C".
5th. Activate the "Midpoint or centre" tool 
and click on points "A" and "C". It will be the point "D", the centre of the arch's starting line.
6th. Click on arch "c". It will be the point "E" that is the centre of the arch.
7th. Activate the "Point" tool 
and click on arch "c". The point "F" appears above the arch.
8th. Activate the "Ray" tool 
and click on points "D" and "F".
9th. Activate the "Move" tool 
and name the ray "s".
Animate point "F" and you will see how the bricks follow the direction of the ray.
The two curved arrows located in the upper right corner of the Graphics View allow you to reset the activity.
If the activity is correct, you will get 10 points automatically.
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2nd. Click on the beginning of the arc located on the left. It will be the point "A".
3rd. Click on the top of the middle arch. It will be the point "B".
4th. Click on the end of the arch located on the right. It will be the point "C".
5th. Activate the "Midpoint or centre" tool and click on points "A" and "C". It will be the point "D", the centre of the arch's starting line.
6th. Click on arch "c". It will be the point "E" that is the centre of the arch.
7th. Activate the "Point" tool and click on arch "c". The point "F" appears above the arch.
8th. Activate the "Ray" tool and click on points "D" and "F".
9th. Activate the "Move" tool and name the ray "s".
Animate point "F" and you will see how the bricks follow the direction of the ray.
The two curved arrows located in the upper right corner of the Graphics View allow you to reset the activity.
If the activity is correct, you will get 10 points automatically.