Lucinda wants to build a square sandbox, but she has no way of measuring angles. explain how she can make sure that the sandbox is square by only measuring length.

Step-by-step explanation:

Given that Luncinda wants to build a square sandbox.  She does not have apparatus to measure angles.

For a square diagonals bisect each other at right angles, and also diagonals are equal.

Draw one line as diagonal. From two ends cut two arcs of equal length by taking more than 1/2 times the diagonal on both sides of the line.

The intersecting points are the two vertices of the square and the end points of the line other two vertices.

This is because by drawing equal length arcs on both sides, we have got isosceles triangles on both sides of the line with same length for equal side both up and down.

This ensures that the square formed has all 4 sides equal, and also diagonals bisect each other at right angles.