see the attactment
thank you
Hello helloying:
Draw a horizontal line through point E.
This forms some right triangles with leg measures of 10 and 17 because point E is vertically and horizontally centered inside the rectangle.
Therefore, the measure of half of angle BEC can be found using the inverse tangent function with the ratio 10/17.
Double the result.
Actually, you do not need the horizontal line because half of angle BEC is the same as the measure of angle BAE. And the ratio 20/34 simplifies to 10/17, which brings us back to the same input for the inverse tangent function.
Cheers,
~ Mark
Is ABCD a rectangle? If so:
1. Split $\displaystyle \angle(BEC)$ into 2 equal parts: $\displaystyle \frac12 \angle(BEC)=\alpha$
2. $\displaystyle \tan(\alpha)=\dfrac{10}{17}~\implies~\alpha\approx 30.466^\circ$
3. Therefore: $\displaystyle \angle(BEC)\approx 60.9^\circ$