Vertical angles ate those that ate directly across from each other and share the same vertex. An example of this would be angles 5 and 7. These types of angles are also congruent, so angles 5 and 7 could be your congruent pair or another set of vertical angles like 1 and 3. A linear pair is two angles that together are a line. Basically, they are next ro each other (divided only by another vector) and are supplementary, adding up to 180 degrees. An example of this in the image is angles 1 and 2.
Answer:

Step-by-step explanation:
step 1
Find the area of the trapezoid (brownie pan)

step 2
To find the number of days , divide the area of the brownie pan by 20 square centimeters of brownie

The easiest way to do this is to multiple 7 and 3, which gives you 21. Julie will spend $21 on the gifts.
I believe the answer is 57