7.1. Draw four rays $O A, O B, O C$ and $O D$ with a common origin such that the drawing contains angles of $100^{\circ}, 110^{\circ}, 120^{\circ}, 130^{\circ}$ and $140^{\circ}$. Write down which angles have the specified measures.
Answer: $\angle A O D=100^{\circ}, \angle A O C=110^{\circ}, \angle A O B=120^{\circ}, \angle B O C=130^{\circ}$, $\angle B O D=140^{\circ} \quad$ (see Fig. 7.1).

For example, one can proceed as follows: first, draw rays $O A, O B$ and $O D$ such that $\angle A O B=120^{\circ}, \angle B O D=140^{\circ}, \angle A O D=100^{\circ}$. This is possible since the sum of these angles is $360^{\circ}$. Then, draw ray $O C$ between the sides of angle $B O D$ such that $\angle C O D=10^{\circ}$, then $\angle A O C=110^{\circ}, \angle B O C=130^{\circ}$.

Evaluation criteria.

“+" A correct drawing is provided and all required angles are correctly recorded

“士" A correct drawing is provided, on which part of the required angles are marked (or recorded separately), and the remaining angles can be uniquely restored

“耳” A plausible drawing is provided, but the required angles cannot be uniquely restored from the available records

“-" An incorrect drawing is provided or it is missing

![](https://cdn.mathpix.com/cropped/2024_05_06_9345244ec41b32b80e18g-1.jpg?height=636&width=511&top_left_y=276&top_left_x=1412)