The problem asks for the measure of angle AEB in a triangle ABC with specific conditions.
Geometric Analysis of Triangle ABC
We are given a triangle ABC where BD is perpendicular to AC at point D. This means $\angle\text{BDC} = 90^{\circ}$.
We are also given that $\angle\text{DBC} = 60^{\circ}$.
Calculating Angles in Triangle BDC
Consider the right-angled triangle BDC:
- The sum of angles in a triangle is $180^{\circ}$.
- In $\triangle\text{BDC}$, we have $\angle\text{BDC} + \angle\text{DBC} + \angle\text{BCD} = 180^{\circ}$.
- Substituting the known values: $90^{\circ} + 60^{\circ} + \angle\text{BCD} = 180^{\circ}$.
- Solving for $\angle\text{BCD}$: $150^{\circ} + \angle\text{BCD} = 180^{\circ}$, which gives $\angle\text{BCD} = 180^{\circ} - 150^{\circ} = 30^{\circ}$.
- Therefore, $\angle\text{BCA} = 30^{\circ}$.
Calculating Angles in Triangle ABC
Now, consider the larger triangle ABC:
- The sum of angles in $\triangle\text{ABC}$ is $180^{\circ}$: $\angle\text{ABC} + \angle\text{BCA} + \angle\text{CAB} = 180^{\circ}$.
- Substitute $\angle\text{BCA} = 30^{\circ}$: $\angle\text{ABC} + 30^{\circ} + \angle\text{CAB} = 180^{\circ}$.
- This simplifies to $\angle\text{ABC} + \angle\text{CAB} = 150^{\circ}$.
Finding Angle AEB
We are given a point E on BC such that $\angle\text{CAE} = 20^{\circ}$. We need to find $\angle\text{AEB}$.
Consider the triangle ABE:
- The sum of angles in $\triangle\text{ABE}$ is $180^{\circ}$: $\angle\text{AEB} + \angle\text{ABE} + \angle\text{BAE} = 180^{\circ}$.
- Note that $\angle\text{ABE}$ is the same as $\angle\text{ABC}$.
- The angle $\angle\text{BAE}$ can be expressed as $\angle\text{CAB} - \angle\text{CAE}$.
- So, $\angle\text{BAE} = \angle\text{CAB} - 20^{\circ}$.
- Substitute these into the angle sum for $\triangle\text{ABE}$: $\angle\text{AEB} + \angle\text{ABC} + (\angle\text{CAB} - 20^{\circ}) = 180^{\circ}$.
- Rearrange the terms: $\angle\text{AEB} + (\angle\text{ABC} + \angle\text{CAB}) - 20^{\circ} = 180^{\circ}$.
- We already found that $\angle\text{ABC} + \angle\text{CAB} = 150^{\circ}$.
- Substitute this value: $\angle\text{AEB} + 150^{\circ} - 20^{\circ} = 180^{\circ}$.
- Simplify: $\angle\text{AEB} + 130^{\circ} = 180^{\circ}$.
- Solve for $\angle\text{AEB}$: $\angle\text{AEB} = 180^{\circ} - 130^{\circ} = 50^{\circ}$.
Thus, the measure of angle AEB is $50^{\circ}$.