Check the picture below.
the triangle has that base and that height, recall that A = 1/2 bh.
now as for the perimeter, you can pretty much count the units off the grid for the segment CB, so let's just find the lengths of AC and AB,
so, add AC + AB + CB, and that's the perimeter of the triangle.
the triangle has that base and that height, recall that A = 1/2 bh.
now as for the perimeter, you can pretty much count the units off the grid for the segment CB, so let's just find the lengths of AC and AB,
so, add AC + AB + CB, and that's the perimeter of the triangle.