Answer:
radian
Step-by-step explanation:
We know that angle for a full circle is 2
In the given figure shape is semicircle
hence,
angle for semicircle will be half of angle of full circle
thus, angle for given figure = half of angle for a full circle = 1/2 * 2
= 
Thus, answer is
radian
alternatively, we also know that angle for a straight line is 180 degrees
and 180 degrees is same as
radian.
Part(A):
To solve the system of Linear equations using Substitution:

Consider the first equation, x+y=7 implies x=7-y













PArt(B): Use a graph to verify your answer to the system:
Using Desmos graphing calculator, graph the two equations.
C=71.91. plug 100 into the equation as x, then solve for C