In a right-angled triangle, the degree measures of external angles are 3: 4: 5. Find the sharp corners of this triangle.

The smallest outer corner of the triangle is right (90 degrees). Based on the ratio given in the conditions, the other two external angles will be equal:

1) (90: 3) * 4 = 120 °;

2) (90: 3) * 5 = 150 °;

The acute angles of the triangle, respectively, will be equal:

1) 180 – 120 = 60 °;

2) 180 – 150 = 30 °.

Answer: The acute angles of the triangle are 60 ° and 30 °.