16) Given a triangle with an angle of 100°. Find the angle α.

Solution:

The image shows a triangle with an angle of 100° and an angle labeled \( \alpha \). It also shows tick marks on two sides, indicating they are equal, making it an isosceles triangle. The third angle is not explicitly given, but there is a right angle symbol at one of the vertices, which is contradictory with the 100° angle.

If we assume the 100° is an angle in the triangle, and it's an isosceles triangle, then the other two angles must be equal. Let these angles be \( x \). Then \( 100^{\circ} + x + x = 180^{\circ} \) \( 2x = 80^{\circ} \) \( x = 40^{\circ} \). So, \( \alpha = 40^{\circ} \).

However, the presence of the right angle symbol contradicts this. If we assume it's a right-angled isosceles triangle, the angles would be 45°, 45°, 90°.

Given the conflict, we will prioritize the isosceles nature and the 100° angle, assuming the right angle symbol is a mistake.

Answer: \(\alpha = 40^{\circ}\)