The arithmetic sequence should have a common difference. If the common difference is positive integer then the arithmetic sequence is in increasing order. If the common difference is negative integer then it will be decreasing order.
easy 230-80 which is 150 so imagine a triangle with base 150 and hight 130-60=70 so times for area 150×70÷2 because it's triangle which is <em>5</em><em>2</em><em>5</em><em>0</em> so plus that with 130x80 for rectangle which is 10400 and add so it's 15650
