In the attachement, there is what I came up with so far. I think that finding 'a' is non-trivial, if possible at all.
- the area of a circle
- the area of a circular segment
That's the second one,
180 - x = r
Whenever two lines cross we get congruent opposite angles and supplemental adjacent angles, i.e. they add to 180 degrees.
The first one is almost right; we have r+y+z=180 and r+x=180 so x=y+z not quite what was written.
Answer:
The correct answer is OB.
Step-by-step explanation:
Let us recall the Associative Property of Addition: given three real numbers 
, 
and 
the following equality holds:
.
Let us remark that the Associative Property of Addition tells us that we can perform the sums in any order. So,
.
In the other options there was used the Commutative Property of Addition.
Answer:
9.75 hours
Step-by-step explanation:
If Rob drove 35% of the time and Mark drove the remainder of the time, the total is 100 %
100-35 = 65
so Mark drove 65% of the time
The total time driven was 15 hours, so we multiply the total time driven by the percentage of time that Mark drove to find the number of hours that Mark drove.
15 * 65%
15*.65
9.75 hours
