Apainter needs to cover a triangular region 60 meters by 68 meters by 71 meters. a can of can cover 70 square meters.. how many cans will be

When we know all 3 sides of a triangle, we can calculate area by using Heron's Formula.  (see attached).  Where s is the SEMI-PERIMETER
perimeter = 60 + 68 +71 = 199
SEMI-Perimeter = 199/2 = 99.5
Area = sq root (99.5 * (99.5-60) * (99.5-68) * (99.5-71)
Area = sq root (99.5 * 39.5 * 31.5 * 28.5)
Area = sq root ( 3,528,381.94 )
Area = 1,878.4 square meters
1,878.4 / 70 sq mtr per can means you will need
26.83 cans OR 27 cans