Answer:
141
Step-by-step explanation:
Subtract 2 from 284(for the length of 1 on each side) and divide 282 by 2 to get 141
B is the right answer
Subtract 14 from each side to get the value of m
21 - 14 = 7 = m
m = 7
2,187
I used a calculator.
21 *78=
20 * 80=
1600 as an estimate
