Answer:
i don't know the perimeter but I do know the area hope this helps if it doesn't I am sorry
Ok for area for a triangle is 1/2 ×base×height and for a semi circle it is pi (π)or 3.14 or 22/7×rsquare with is radius x radius
Explanation:
lets start with the triangle so it is 1/2×3/1×5/1×4/1 =30/1 =30sqkm
now for the semi circle it is 22/7×2/1×2/1=88/7=12.5÷2=6.2 why is 4/1 turned into 2/1 it is because you are finding area and 4 is the diameter but we need radius so the radius is half of the diameter
so 30+6.2=36.2kmsq