First, find the area of the larger triangle:
A=1/2bh
A=1/2(702)
A=351 square yards
Second, find the area of the smaller triangle:
A=1/2bh
A=1/2(225)
A=112.5
To find the shaded area subtract 112.5 from 351:
351-112.5 = 238.5
The area of the shaded region is 238.5 square meters