The diagram below consists of a small square, four equilateral triangles, and a large square. Find the area of the large square.
Alarge square = 6.25 units2
The base of each triangle is 1 unit.
There are 21/2 bases going across.
So the side of the square is 21/2 units.
Two and a half squared is six and a quarter.
.
+250 
