Hey so yeah this can be a challenging problem, Vol (V) is much easier to solve than surface area (SA), but I'll show you how it's done, my friend.
First of all, V (prism) = area of base (B) × h
We know that the height (h) of this prism is given, which we'll need later on: h = 5 ft, and area of base (B) is given as 60 ft2
So V = 60 ft2 × 5 ft = 300 ft3
So now for the hard part... how to calculate the SA of this prism
IF YOU DON'T NEED SA FOR THIS TYPE OF PROBLEM, DO NOT PROCEED!!!
[VERY DETAILED]
means solving the dimensions (sides) of that pesky polygon base (B) or lid.
The most important things about polygons are:
1) is it regular (same angle ° and side length)??
2) How many sides or angles??
This has to be regular, because they give you no other info so it has to be, in order to solve. And then it has 5 sides and angles = regular pentagon. ("penta" means 5).
Now there are 360° in any circle, so:
take the central angles of where the sides meet at the center forming triangles (see drawing above), each of those (5) central <'s = 360/5 = 72°
Now the apex of each of these triangles = 72°
but with our 5 triangles, we need to find the height of each triangle -- which is the midpoint of the side (base (b) of triangle), and h is perpendicular to this b. By bisecting that apex angle of 72, it forms 2 equal right triangles of
72/2 = 36°. So each right triangle has 36, 90, and?? 180-36-90 = 90-36 = 54°
let's call the base (b) = 1 side of pentagon
= side (s)
Therefore (see 2nd image drawn above) tangent (tan) of € = opposite/adjacent, or
tan (54) = h÷1/2b --> h = [tan (54)]×(1/2)b
1/2b = h/[tan (54)] = h/1.38
Also the area of each of the larger 5 triangles A(t) = 1/2b×h, and that area A(t) × 5 = area of whole pentagon base A(B)
So now after all that... our A(B) given at beginning = 60ft2. let's put it all together:
1/2b = h/[tan (54)] = h/1.38
A(t) = 1/2b×h, and A(B) = 5×A(t)
which means that A(B) = 5×(1/2b×h)
AND since the other calculation shows that 1/2b = h/1.38, plug that value into the A(B) formula...
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.
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now that we have height (h) of each triangle, we can go back to our tan equation for the triangle: tan (54) = 1.38 = h/(1/2b)
--> 1/2×b = h/1.38 --> base (b) = 2h/1.38
b = 2(4.06 ft)/1.38 = 8.12 ft/1.38 = 5.90 ft, for which b us also the width of each rectangular side panel (w)
length (l) of these sides was given as height of the whole prism = 5 ft
NOW FINALLY... THE FINAL SURFACE AREA OF THE PRISM (SA) = (2×A(B)) + (5×rectangular side)
SA = (2×60 ft2) + (5×(l×w)) = 120 ft2 + 5×5ft×5.9ft
SA = 120 ft2 + 147.62 ft2 = 267.62 ft2
Step-by-step explanation:
1075 students were asked how close they live to the college. The table shows the results below with some values missing. Enter the correct values in the boxes remembering to use the % symbol where necessary.
<u>20 to 25: </u>given 20%
20% of 1,075 = 215
<u>15 to 19: </u>given 12%
12% of 1,075 = 129
<u>10 to 14: </u>given 516 students
(516/1,075)*100 = 48%
<u>5 to 9: </u>given 162 students
(162/1,075)*100 = 15.07%
<u>< 5: </u>given 53 students
(53/1,075)*100 = 4.93%
Answer:
17.5%
Step-by-step explanation:
take 25% x 1/2..............
Answer:
anything raised to the power of zero= 1
(1+1/4^½)²
(1 + 1/2)²
(3/2)²
9/4
=2.25
Answer:
28 cubs
Step-by-step explanation:
Since one and a half bear produces one and a half cub, then 6 bears will produce 6 cubs in one and a half days.
We need to find 7 days, though but we have the rate for six bears for 1.5 days which 6 bears one a half day.
What is the rate for a day?
6/1.5 =
6 bears produce 4 cubs a day.
Now just do 4 x 7
4 x 7 = 28
Therefore, 6 bears produce 28 cubs in 7 days.
