Find the angles of a convex quadrilateral if they are proportional to the numbers 1245.

Let’s solve the problem using the equation.
Let the degree measure of angle C be x degrees, the degree measure of angle D is 2 * x degrees, the degree measure of angle E is 4 * x, the degree measure of angle A is 5 * x degrees. We know that the sum of the degree measures of a convex quadrilateral is 360 degrees. Let’s make the equation:
x + 2 * x + 4 * x + 5 * x = 360;
x * (1 + 2 + 4 + 5) = 180;
x * 12 = 180;
x = 30 degrees – the degree measure of the angle C;
2 * 30 = 60 degrees – the degree measure of the angle D;
4 * 30 = 120 degrees – the degree measure of the angle E;
5 * 30 = 150 degrees – the degree measure of angle A.
Answer: 30 degrees; 60 degrees; 120 degrees; 150 degrees.