Question

Find the missing angle θ in Figure 1.11(a). (The right angles in the figure are marked.)

Figure 1.11

Answer 1

It will help to first find the length of the side marked y in Fig. 1.11(b). Since y and the side of length 2.60 are the opposite and adjacent sides of the 45◦ angle, we have:

Figure 1.11:

We can write a similar relation for the missing angle,

Using the inverse tangent operation,

The missing angle is 60.0^◦ .