Answer:

Step-by-step explanation:

Using this rule we have:

Answer:
580
Step-by-step explanation:
Answer:
59.15 in^2
Step-by-step explanation:
Using Heron's formula
semiperimeter , s = 1/2 ( 28.8+18+12) = 29.4
Area = sqrt ( 29.4(29.4-28.8)(29.4-18)(29.4-12) ) = 59.15 in^2