Length in units:
Use phytogoras theorem or measure it by a ruler if your using a graph paper
AB = 5.65 units
AC = 5.83 units
CB = 1.41 units
Perimeter =5.65 + 5.83 + 1.41 = 12.89 units
Area = 1/2 * 1.41 * 5.65 = 3.98units
First I would find the base, which is a square so 10x10=100
then find the triangle (a=1/2bh) a=1/2(12)(10) a=1/2(120) a=60
since there are four triangle sides do 60x4 which equals 240, so then add the sides to the base 100+240=340, the answer is A
12 5/25 as a simplified mixed number would be 12 1/5
It’s 28 divided by 7 x 15 -13
How do I know ? I’m in high school and I just worked it out !!