Answer:
252 sq. in.
Step-by-step explanation:
divide it into sections like this
12*15=180
3*6=18
6*9=54
then add it all together. sometimes it is more complicated, but as long as none of the divided parts overlap this will be correct for any shape, as long as you account for the whole shape.
6. B
7. C
8. B
9. D
10. C
11. B
12. 7
Hope I could help! You got numbers 6,8, and 9 wrong, but everything else correct so not bad!
120 + 90 = 210 points
350 - 210 = 140 OR
351 - 210 = 141 (if it must be more than 350, you need <em>at least </em>351 points total, or 141 more points, to get a grade B)
So basically you proportionize the triangles.
1) 52/x=20/5
2)cross multiply, you get--> 20x=260
3)divide 20 both sides, you get --> ×=13