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jenyasd209 [6]
3 years ago
9

The perimeter of equilateral triangle is 21m. Find the area. Using Heron's Formula

Mathematics
1 answer:
Alecsey [184]3 years ago
5 0

Answer:

A ≈ 21.22 m²

Step-by-step explanation:

The area (A) of a triangle using Heron's formula is

A = \sqrt{s(s-a)(s-b)(s-c)}

where s is the semi perimeter and a, b, c the sides of the triangle.

Here the perimeter of the equilateral triangle is 21 m , then

a = b = c = 21 ÷ 3 = 7 m

s = 21 ÷ 2 = 10.5

Then

A = \sqrt{10.5(10.5-7)(10.5-7)(10.5-7)}

   = \sqrt{10.5(3.5)(3.5)(3.5)}

   = \sqrt{450.1875}

   ≈ 21.22 m² ( to 2 dec. places )

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Part B
lianna [129]

Answer:

Soccer: 19 Males

Basketball: 29 females

Total: 40 males, 60 females

Step-by-step explanation:

                         MALES     FEMALES   TOTAL

SOCCER        ║     19     ║      31       ║    50   ║

BASKETBALL║     21      ║      29      ║    50   ║

TOTAL           ║     40     ║      60     ║   100   ║

[OPTIONS ⇒ 19, 29, 40, 60]

<u>SOCCER:</u>

x + 31 = 50

50 − 31 = 19

<em>19 males</em>

<em />

<u>BASKETBALL</u>

21 + y = 50

50 − 21 = 29

<em>29 females</em>

<em />

<u>TOTAL:</u>

F: 31 + 29 = 60

M: 19 + 21 = 40

60 + 40 = 100

<em>60 females </em>

<em>40 males</em>

6 0
3 years ago
Mrs. Wang is 23 years older than her daughter. In 5 years, their age will total 63. How old are they now?
ella [17]
Daughter is 35 and mother is 58
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3 years ago
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Antonia is factoring the polynomial, which has four terms. 7x3 – 21x2 + 5x – 15 7x2(x – 3) + 5(x –3) Which is the completely fac
Vikentia [17]
Factoring out (x-3), we get (7x^2+5) (x-3). That is your answer, I hope this helps :).
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The largest doll is 12 inches tall. The height of each of the other dolls is 710 the height of the next larger doll. Write an ex
Ahat [919]
Largest doll = 12 inches
2nd doll = (12) x 0.7
3rd doll = (12 x 0.7) x 0.7
4th doll = [(12 x 0.7) x 0.7) x 0.7

So, the height of the nth doll can be expressed as: 12 x 0.7^(n-1)

Example: 4th doll = 12 x 0.7^(4-1) = 12 x 0.7^3
6 0
3 years ago
3 QUESTIONS !
Nadusha1986 [10]

Answer:

1) 4

2) 45

3) 104

Step-by-step explanation:

1)

let x be your number.

((6x+8)/4)-5 = 3

add 5

(6x+8)/4=8

multiply by 4 to get rid of the denominator

6x+8=32

subtract 8

6x=24

divide by 6

x=4

2) Same type. (this time I won't explain every step)

let x be your number

((x/9)-8+6)*7 =21

(x/9)-8+6=3

(x/9)-2=3

x/9 = 5

x=45

3) Same type... Again

let x be your number

(((x-4+11)*2)/6)-8 = 29

((x-4+11)*2)/6=37

(x-4+11)*2 = 222

x+7=111

x= 104

6 0
3 years ago
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