__Instruction:__ Given two vertices of a square. Construct the two other vertices using only a compass.

__Goal:__ 7L 7E
Available tools:

- Move
- Point
- Circle
- Intersect

__Pack:__ Delta

__Previous level:__ 4.10

__Next level:__ 5.1

## 7L 7E solution[]

Let A and B be the given vertices.

- Construct the circle with center A and radius AB
- Construct the circle with center B and radius AB, intersecting circle A at C and D
- Construct the circle with center C and radius CD, intersecting circle A at E and circle B at F
- Construct the circle with center E and radius BE
- Construct the circle with center F and radius AF, intersecting circle E at G and H
- Construct the circle with center A and radius AG, intersecting circle B at I and J, with I on the same side as G from AB
- Construct the circle with center B and radius BG, intersecting circle A radius AB at K and L, with K on the same side as I from AB
- Point at I
- Point at K

## 3V solution[]

- Point at J
- Point at L
- Construct the circle with center G and radius GI, intersecting circle A at M and circle B at N
- Construct the circle with center K and radius KM
- Construct the circle with center I and radius IN, intersecting circle K at O
- Construct the circle with center A and radius AO
- Construct the circle with center B and radius BO, intersecting circle A radius AO at P
- Point at P