Plz help! I'm really confused!

The diagram below consists of a small square, four equilateral triangles, and a large square. Find the area of the large square.

A_{large square} = 6.25 units^{2}

The base of each triangle is 1 unit.

There are 2^{1}/_{2} bases going across.

So the side of the square is 2^{1}/_{2} units.

Two and a half squared is six and a quarter.

_{.}

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