Answer:
Let's find the height:
Half of 8 is 4.
4^2 + 8^2 = 80
80(lets find the square root of 80): 8.944 ^2 = 79.995136 close enough to 80
Your new height is 8.944.
8 x 8.944 = 71.552, 71.552 x 1/2 (basically just dividing by 2) = 35.776 rounded would be = 35.78 cm^2
Formula of area of a triangle:
B(base)H(height) x 1/2(basically just dividing by 2)
In this case 8 is your base and 8.944 is your height.