David was solving the following problem “determine 80% of 10” and got 80. Where did David go wrong? Show your Work!

Answer:

58.4197cm^2

Step-by-step explanation

cirlce area formula: [tex]\pi[/tex]r^2

r= 6.1

[tex]\pi[/tex]=3.14

Now plug numbers into the formula

area of circle:

= (3.14)(6.1^2)

=(3.14)(37.21)

= 116.8394cm^2  ------> area of full circle

now divide by 2, to find area of semi circle

116.8394/2= 58.4197cm^2

[tex] \huge\fbox\red{A}\fbox\pink{n}\fbox\purple{S}\fbox\green{w}\fbox\blue{E}\fbox\orange{r}[/tex]

area of semicircle is 58.572 m²

[tex] \huge \sf { \fcolorbox{green}{g}{Explanation :- }}[/tex]

[tex] \huge \underline{\large \fbox \red{Concept : }}[/tex]

We have to find the area of semicircle

So firstly we need to find the area of circle. because the semicircle of circle is the half of area of circle so first we find the area of circle then divide by 1 /2 then we get the area of semicircle.

We have given the radius of circle is 6.1 m

[tex]\huge\mathfrak\red{Solution : }[/tex]

[tex] \mathfrak \green{Area \: of \: circle = π × ( radius) ²}[/tex]

[tex]\mapsto \: \: \small \: \: \: \: \: \mathfrak \blue{ = \frac{22}{7} \: \times( 6.1 \: m)^{2} } \\ [/tex]

[tex]\mapsto \small \: \: \: \: \: \mathfrak \blue{ = \frac{22}{7} \: \times37.21 \: m {}^{2} } \\ [/tex]

[tex]\mapsto \: \small\: \: \: \: \: \: \mathfrak \blue{ = 116.94 \: m {}^{2} }[/tex]

Therefore,

[tex]\small \mathfrak \red{Area \: of \: semicircle = \frac{1}{2} \times area \: of \: circle}[/tex]

[tex] \small \mathfrak \green{ = \frac{1}{2} \times 116.94 \: cm \: {}^{2} } \\ [/tex]

[tex]\mapsto \: \small\: \: \: \: \: \: \mathfrak { = 58.472\: m {}^{2} }[/tex]

[tex] {\underline {\fbox\red{Hence, the area of semicircle is 58.572 m²}}}[/tex]

Answer: Not a right-angled triangle

Step-by-step explanation:

Given

The sides of a triangle are [tex]7\ m, 8\ m, \text{and}\ 10\ m[/tex]

For a right-angle triangle, it must satisfy the Pythagoras theorem

[tex]a^2+b^2=c^2[/tex]

i.e. the square of the larger side must be equal to the sum of the square of the remaining two sides

Here,

[tex]\Rightarrow 7^2+8^2\ ?\ 10^2\\\Rightarrow 49+64\ ?\ 100\\\Rightarrow 113\neq 100[/tex]

Therefore, it is not a right-angle triangle

[tex]5x + x + y + 2x = 180 \\ y = 28 \\ 5x + x + 28 + 2x = 180 \\ 8x + 28 = 180 \\ 8x = 180 - 28 \\ 8x = 152 \\ x = 19[/tex]

Answer:

On the sixth day (10 - 4), the worm was 2.5mm long.

Step-by-step explanation:

Giving the following information:

Future Value= 40mm

Present Value= 2.5mm

Number of periods (n)= ?

Growth rate= 100% per day

First, we need to calculate the number of days it will take to grow from 2.5mm (PV) to 40mm (FV):

n= ln(FV/PV) / ln(1+i)  

n= ln (40 / 2.5) / ln (2)

n= 4

It will take 4 days.

On the sixth day (10 - 4), the worm was 2.5mm long.

Answer:

Step-by-step explanation:

Given is 1

Corresponding angles Postulate is 2

Substitution is 4

Same side theorem is 3

Answer:

D.115

Step-by-step explanation:

Use the exterior angle of a triangle theorem which states that the exterior angle of a triangle is equal to the sum of the opposite interior angles meaning D=C+B

Answer:

80 songs per month.

Step-by-step explanation:

There are 12 months in a year

So you do 960 divided by 12 to see how many songs he sang per month

And you get 80.

Answer:

He did not square 40, he just multiplied by 2

Answer 41 centimeters.

Step-by-step explanation:

C²=40²+9²

C²=1600+81

C²=1681

√c²=√1681

C=41cm

Answer:

the answer is A

Step-by-step explanation:

edg

Answer:

1+X < 52

6 < Y- 4

Step-by-step explanation:

btw y did u report me on

https://brainly.com/question/22537441

Answer:

B) 50

Step-by-step explanation:

<A = x + 53

x + 53 + x + 83 + 50 = 180

2x + 186 = 180

2x = -6

x = -3

<A = x + 53

-3 + 53

50

Answer: 130 cm

Step-by-step explanation:

Let's take the equation for the volume of a rectangular prism

V=Length * Width * Height (L*W*H)

[tex]V=W*L*H[/tex]

V=2*13*5

[tex]V=2*13*5[/tex]

V=130 cm

[tex]V=130cm[/tex]

Answer:

Step-by-step explanation:

Antonio’s rate is 1/6 while Emilia’s rate is 1/4 while working alone, together they will complete the job when.

t/6+t/4=1 making common denominators

(t/6)(2/2)+(t/4)(3/3)=1

(2t+3t)/12=1

5t=12

t=2.4 hours (or 2 hours and 24 minutes)

Answer:

cannot factor further

Step-by-step explanation:

step 1: search online for factoring calculator

step 2: pick a site to use

step 3: enter problem and hit enter

step 4: see full solutions.

sorry I couldn't help more

Answer:

136 cm²

Steps:

LA = π × 8 × √(15²+8²)

LA = π × 8 × √(225+64)

LA = π × 8 × √(289)

LA = π × 8 × 17

LA = π × 136 cm²

Answer:

1.A=bh/2

2A=bh

2A/b=h

  answer                   check

2.f(x)=21-6x               f(5)=21-6(5)            

 g(x)=2x/5-11            f(5)=21-30

21-6x=2x/5-11            f(5)=-9

21=32x/5-11              g(5)=2(5)/5-11

(5)32=32x/5(5)         g(5)= 10/5-11

160=32x                    g(5)=2-11

5=x                             g(5)=-9

3. f(7)=3(7)-7

   f(7)= 21-7

   f(7)= 14

Step-by-step explanation:

Answer:

A and D

Step-by-step explanation:

Answer:  B

Step-by-step explanation: first you have to find the square root of 9 (81) then multiply that by 11 which is 891

Answer:

9(p + 9)

Step-by-step explanation:

9p + 81

Lets take 9 common from the expression.

⇒ 9(p + 9)

Answer:

9(9+p)

Step-by-step explanation:

9(9+p) = 81 + p

Answer:

A. Length

Step-by-step explanation:

Betty wants to put new cabinets in her kitchen. She measures one side of her kitchen and finds it measures 18 meters.

Which measurement did Betty find?

A. Length

B. Perimeter

C. Area

The measurements Betty found is the length of the cabinet

A side of the cabinet is equivalent to the length of such cabinet

To find the perimeter of the cabinet, it requires the addition of all the sides of the cabinet.

To find the area of the cabinet, it requires the multiplication of two different sides of the cabinet.

Therefore, Betty has only measured the length of the cabinet

Answer:

Ram will cover 25 km in 100 min's

Step-by-step explanation:

Hope this helps (^w^)

Answer:

hello :> UvU

Step-by-step explanation:

Answer:

Yes

Step-by-step explanation:

Scale factor is the ratio of the length of one side of a point/figure to a similar side in another point or figure.

The scale factor can either be less than one(1) or greater than one(1) depending on the figure/ point you begin from when finding the scale factor.

Hence you can find the scale factor for a point with 2 different scale factors

Answer:

A

Step-by-step explanation:

Answer:

3c

Step-by-step explanation:

If the temperature is seceding everyday I can only guess the next day it decreases.

The minimum amount of fabric needed for a sandbox is,

⇒ 72 feet²

We have to given that;

A sandbox in the shape of a trapezoid is show below.

And, a cover is to be made for the sandbox.

Hence,

The minimum amount of fabric needed for a sandbox is,

⇒ Area of fabric = 9 × 7 + (1/2 × 9 × 2)

                         = 63 + 9

                         = 72 feet²

Thus, The minimum amount of fabric needed for a sandbox is,

⇒ 72 feet²

Learn more about the multiplication visit:

https://brainly.com/question/10873737

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Answer:

61°

Step-by-step explanation:

In order for triangle LMN and PQR to be congruent, angle M and angle Q must equal. thus, we can set 2x-26=x+16

with basic algebraic manipulation, x=42. we then plug it back into the angle M or Q, getting angle M/Q= 58°

since this is a isoceles, the 2 base angle are identical, so 180= 58+2(angle P)

thus, angle P= 61