A=(AB+CD)*h/2
A=(12+19)*9/2=31*9/2=279/2=139,5 in.^2
It’s 6 thanks duehwyahahahsh
Answer:
For example the age of the Earth (see above) can be written as 4.6 X 109 years. This means that this number has 9 places after the decimal place - filled with zeros unless a number comes after the decimal when writing scientific notation. So 4.6 X 109 years represents 4600000000 years.