The angles of the triangle are in the ratio 3: 7: 8. Then the outer angle adjacent to the large angle of the triangle is.

Since the angles of this triangle are 3: 7: 8, let’s take their values equal to 3x, 7x and 8x. The sum of the angles of a triangle is 180 °, which means:

3x + 7x + 8x = 180;

18x = 180;

x = 180/18 = 10.

Therefore, the greater angle of this triangle is 8 * x = 8 * 10 = 80 °.

The sum of the adjacent angles is 180 °, so the angle adjacent to the large angle of the triangle defined by the condition is 180 – 80 = 100 °.