Answer:
1..JANE FISH FIRST.
2..BEN WAS LAST.
3..20 MIN AHEAD OF RITA
4..BEN WAS 25 MIN BEHIND ALL AND 5 MIN BEHIND RITA
5..9.45 IS THE AVERAGE TIME OF 3 STUDENTS
Step-by-step explanation:
<h3>MARK AS BRAINLIAST</h3>
1: 8 faces and 9 with the base 9 vertices and 16 edges
2: 3 faces and 5 with the bases 6 vertices and 9 edges
3: 3 faces and 4 with the base 4 vertices and 6 edges
Hope this can help you.
Answer:
45
Step-by-step explanation:
AEF is a similar triangle to ABC. that means it has the same angles, and the sides (and all other lines in the triangle) are scaled from the ABC length to the AEF length by the same factor f.
now, what is f ?
we know this from the relation of AC to FA.
FA = 12 mm
AC = 12 + 28 = 40 mm
so, going from AC to FA we multiply AC by f so that
AC × f = FA
40 × f = 12
f = 12/40 = 3/10
all other sides, heights, ... if ABC translate to their smaller counterparts in AEF by that multiplication with f (= 3/10).
the area of a triangle is
baseline × height / 2
aABC = 500
and because of the similarity we don't need to calculate the side and height in absolute numbers. we can use the relative sizes by referring to the original dimensions and the scaling factor f.
baseline small = baseline large × f
height small = height large × f
we know that
baseline large × height large / 2 = 500
baseline large × height large = 1000
aAEF = baseline small × height small / 2 =
= baseline large × f × height large × f / 2 =
= baseline large × height large × f² / 2 =
= 1000 × f² / 2 = 500 × f² = 500 ×(3/10)² =
= 500 × 9/100 = 5 × 9 = 45 mm²
Answer:
B
Step-by-step explanation:
Note the common difference between consecutive terms of the sequence.
d = 16 - 12 = 20 - 16 = 4
This indicates the sequence is arithmetic with sum to n terms
= 
[2a₁ + (n - 1)d ]
where a₁ is the first term and d the common difference
Here a₁ = 12 and d = 4, thus
= 
[ (2 × 12) + (41 × 4) ]
= 21( 24 + 164) = 21 × 188 = 3948 → B
