Answer:
i.
Step-by-step explanation:
.
Answer:
See Below
Step-by-step explanation:
The surface area of cylinder is given by the formula:

Where
r is radius ( diameter is 4, so radius is 4/2 = 2)
h is height ( h = 9)
Lets find original surface are:

<u>Halving diameter:</u>
diameter would be 4/2 = 2, so radius would be 2/2 = 1
So, SA would be:

<u>Halving height:</u>
Height is 9, halving would make it 9/2 = 4.5
Now, calculating new SA:

Original SA is
,
Halving diameter makes it 
Halving height makes it 
So, halving diameter does not have same effect as halving height.
Answer:
∠1 = ∠3 = 54°; ∠2 = 36°
Step-by-step explanation:
Each of the triangles is isosceles. Triangles opposite each other are congruent, so ∠2 is congruent to 36°.
∠2 and ∠3 are complementary, so ∠3 is 54°. Since ∠3 is congruent to ∠1, it, too, is 54°.
Answer:
-18 3/4
Step-by-step explanation: