How do you turn 12.576 into expanded form explain

The angle of a triangle are given as 6x,(x-3), and (3x+7). find x then find the measures of the angles

Match the scale and the actual area to the area of the corresponding scale drawing. scale: 1 inch to 4 feet actual area: 128 square feet scale: 1 inch to 7 feet actual area: 147 square feet scale: 1 inch to 8 feet actual area: 256 square feet scale: 1 inch to 5 feet actual area: 225 square feet area of scale drawing scale and actual area scale drawing area: 3 square inches arrowright scale drawing area: 8 square inches arrowright scale drawing area: 4 square inches arrowright scale drawing area: 9 square inches arrowright

I'm a polygon i have no parallel lines i am formed 3 line segments i have one right angle two of my angles are angles what am i