[填空题]
In this question give all angle:xrzs6)n,l tro0 6- bqtdw1 t zkj/wi:s 2zhlw:i6oms,w fla34l em-)q in radians.
Let $z=1+2 \mathrm{i}$ and $w=4+\mathrm{i}$ .
1. Find z+w . a+bi a = b =
2. Find:
1. $|z+w|$ ;≈
2. $\arg (z+w)$ .≈
3. Find $\theta $, the angle shown on the diagram below.≈
