Which number has two lines of symmetry? 101 619 33 18

find the area of the trapezium whose parallel sides are 25 cm and 13 cm The Other sides of a Trapezium are 15 cm and 15 CM

Snezhnost [94]

$\huge\underline{\red{A}\blue{n}\pink{s}\purple{w}\orange{e}\green{r} -}$

Given - A trapezium ABCD with non parallel sides of measure 15 cm each ! along , the parallel sides are of measure 13 cm and 25 cm

To find - Area of trapezium

Refer the figure attached ~

In the given figure ,

AB = 25 cm

BC = AD = 15 cm

CD = 13 cm

Construction -

$draw \: CE \: \parallel \: AD \: \\ and \: CD \: \perp \: AE$

Now , we can clearly see that AECD is a parallelogram !

$\therefore$ AE = CD = 13 cm

Now ,

$AB = AE + BE \\\implies \: BE =AB - AE \\ \implies \: BE = 25 - 13 \\ \implies \: BE = 12 \: cm$

Now , In ∆ BCE ,

$semi \: perimeter \: (s) = \frac{15 + 15 + 12}{2} \\ \\ \implies \: s = \frac{42}{2} = 21 \: cm$

Now , by Heron's formula

$area \: of \: \triangle \: BCE = \sqrt{s(s - a)(s - b)(s - c)} \\ \implies \sqrt{21(21 - 15)(21 - 15)(21 - 12)} \\ \implies \: 21 \times 6 \times 6 \times 9 \\ \implies \: 12 \sqrt{21} \: cm {}^{2}$

Also ,

$area \: of \: \triangle \: = \frac{1}{2} \times base \times height \\ \\\implies 18 \sqrt{21} = \: \frac{1}{\cancel2} \times \cancel12 \times height \\ \\ \implies \: 18 \sqrt{21} = 6 \times height \\ \\ \implies \: height = \frac{\cancel{18} \sqrt{21} }{ \cancel 6} \\ \\ \implies \: height = 3 \sqrt{21} \: cm {}^{2}$

Since we've obtained the height now , we can easily find out the area of trapezium !

$Area \: of \: trapezium = \frac{1}{2} \times(sum \: of \:parallel \: sides) \times height \\ \\ \implies \: \frac{1}{2} \times (25 + 13) \times 3 \sqrt{21} \\ \\ \implies \: \frac{1}{\cancel2} \times \cancel{38 }\times 3 \sqrt{21} \\ \\ \implies \: 19 \times 3 \sqrt{21} \: cm {}^{2} \\ \\ \implies \: 57 \sqrt{21} \: cm {}^{2}$

hope helpful :D

6 0

2 years ago

The N71-90 virus will give an infected person a mild rash on their arms once the person has 1 billion of the virus cells in thei

Naya [18.7K]

Answer:

B. 256

Step-by-step explanation:

Given function:

v(h) = 2^(h/4)

It can be rewritten as:

v(d) = 2^d, where d- number of divisions

If number of divisions is 8, then:

v(8) = 2^8 = 256 virus cells

Correct choice is B

4 0

3 years ago

Read 2 more answers

6. Find how long it takes $600 to double if it is invested at 12%

ioda

Answer:

A = $697.09

Step-by-step explanation:

A = P (1 + r/n)

A = 600 (1 + 0.05/365)

A = $697.09

5 0

3 years ago

FIRST TO ANSWER GETS BRAINLIEST: The average age of one hundred Year 9 students is 14 y 10 m. The average age of one hundred Yea

Dvinal [7]

Answer:

2) 14 y 2 m

Step-by-step explanation:

Year 9 students: total age= 100* 14 10/12= 1400 +100*5/6= 1483 y 8 m

Year 8 students: total age= 100* 13 6/12= 1350 y

Total age of 200 students: 1483 y 8 m + 1350 y= 2833 y 8 m

Average age= 2833 8/12 ÷ 200= (12*2833+8)/12 ÷ 200 = 34004/(12*200)= 34004/2400= 14 404/2400 ≈ 14 1/6 y= 14 y 2 m

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3 years ago

Help me solve please

Elodia [21]

1. X = 83
2. X = 101
3. X = 24

3 0

3 years ago