Answer:
The measure of the reference angle is 
Step-by-step explanation:
The reference angle of an angle is the magnitude of the smallest angle it makes with the x-axis. In this case, we have 
(*Note: 
, use 
to convert to degrees)
Answer:
When we say an angle is on a circle, we mean the vertex is on the edge of the circle. One type of angle on a circle is the inscribed angle (see Inscribed Angles in Circles). Another type of angle on a circle is one formed by a tangent and a chord.
Answer: 3 different ways
Those three ways, I'll label as A, B, and C
A) Buying the 78 cookies one at a time
B) Buying 6 packs of the 13-count cookies, so 13*6 = 78 cookies total.
C) Buying 2 packs of the 39-count cookies, so 2*39 = 78 cookies total
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For option A, we can imagine a rectangle that is 1 unit high and 78 units long giving an area of 1*78 = 78. Or we can imagine a single row of 78 cookies in this row.
In option B, we can have a rectangle that is 13 by 6, giving an area of 78. Or We could have 6 rows of 13 cookies per row (each row representing a package of cookies).
Option C would be similar to B, instead there would be 2 rows of 39 cookies per row.
