So, the reason a triangle has an area of bh/2 is because it's half a rectangle. Draw a diagonal across a square and you have to right angles.
a2 + b2 = 1102
Hey, since it's a square, a and b are the same.
2a2 = 12,100
a2 = 6050
a = √6050 = 77.78 m
The area is given above, 6050 m2.