−
9
Explanation:
(
3
i
)
2
=
9
i
2
i
2
=
−
1
,
therefore,
9
i
2
=
9
⋅
(
−
1
)
=
−
9
Simple..
there is a major difference between 6z and

6z means: 6 times z
and

means: z to the power of 6(z*z*z*z*z*z)
An example...
make z=2...plug n chug..
6z----> 6(2)=12
and

--->

=64
As you can see..there is a
major difference.
Thus, your answer.
Answer:
yes, this is proportional
the sum of the interior angles is 180° (triangles)
it's isosceles, 2 equal sides and 2 equal angles.
you take away the given angle from 360° and you will find the sum of the 2 equal sides, you divide by 2 and you have the angle b (equal to angle C).
(180 - 72) : 2 =
108 : 2 = 54° (your answer)
-----------------------
72 + 54 + 54 = 180°
The answer is good.