Answer:
3.9
Step-by-step explanation:
3.8<u>5</u>215 Since your rounding to the nearest tenth which is 8 you will look at the number to the right which is 5. If the number is 5 or greater than five then the number in the tenth place will go up one. So it becomes 3.9.
It is rounded to 3.9 I think
531 in^2
21 x 18 = 378 in^2
17 x 9 = 153 in^2
378 + 153 = 531 in^2
S1 is congruent to S2