Can somone pls help me .. will mark u brainliest !

What is the circumference of the circle? Use 3.14 for pi 4 in. Diameter

navik [9.2K]

Answer:

12.56 inches

Step-by-step explanation:

Circumference of circle = 3.14 × Diameter

= 3.14 × 4 inches

= 12.56 inches

3 0

3 years ago

What is the percent of change from 58 to 29? also thank you guys for helping me?

zhannawk [14.2K]

It's a percent decrease and it decreases by -50%

8 0

4 years ago

Help me please :) its very hard

postnew [5]

Answer:

Answer B

Step-by-step explanation:

You need to first find the surface area of the triangular prism.

In order to do that, we need to first know the length of the base of the triangles on both side. So, I used the pythagorean theorem (a²+b²=c²) after making the triangle a right triangle by cutting it in HALF.

a²+b²=c²

a²+2.6²=3²

a²+6.76=9

Subtract 6.76 on both sides

a²=2.24

a=√2.24

a=1.49666295471

Now, we know that the base of HALF of the triangles on both sides of the prism is 1.496......

We need to MULTIPLY this by 2 to get the full length. So, the length of the bases of both triangles is 2.99332590942

The height of the triangles is 2.6

We are going to first find the area of one triangle and multiply it by 2, to get the area of both triangles.

Area of a triangle = base x height ÷ 2

2.6 x 2.99332590942= 7.78264736449

7.78264736449 ÷ 2 = 3.89132368224

3.89132368224 x 2 (because we have 2 triangles) =7.78264736449 cm squared

Now, we know the area of both triangles, but we now need to add the add the surface area of the rectangles in the net.

Area of a rectangle = length x width

We know that all of the three rectangles are equal in size, and that the length of each one of them is 15 cm. However, the width/height of each one is unknown. We will find out the height of each one by looking at the length of the base of the triangle attached to the first one. We know that because of the base of the triangles = 2.99332590942, the width of the attached rectangles are 2.99332590942. We found this using the Pythagorean theroem (look above).

15 x 2.99332590942= 44.8998886413

44.8998886413 x 3 (because we have 3 of the same rectangles)= 134.699665924 cm squared

Now, we must ADD the surface area of the rectangles AND the triangles.

7.78264736449 (triangles) + 134.699665924 (the three rectangles)= 142.482313288 cm squared.

The CLOSEST OPTION to the answer we got is ANSWER B because it is 142.8 cm squared, which is the closest to the answer we got which was 142.482313288 cm squared.

I really hope this helps :)

6 0

3 years ago

Read 2 more answers

Solve with solution...no spam answers pls

Agata [3.3K]

Let's analyze Hannah's work, step-by-step, to see if she made any mistakes.

In Step 1, Hannah wrote $\dfrac{d}{dx} (-3+8x)$ as the sum of two separate derivatives $\dfrac{d}{dx}(-3)+ \dfrac{d}{dx} (8x)$ using the sum rule.

This step is perfectly fine.

In Step 2, $\dfrac{d}{dx}(8x)$ was kept as it is, and $\dfrac{d}{dx}(-3)$ was rewritten as $0$ using the constant rule.Indeed, according to the constant rule, the derivative of a constant number is equal to zero.

This step is perfectly fine.

In Step 3, $\dfrac{d}{dx} (8x)$ was rewritten as $\dfrac{d}{dx}(8) \dfrac{d}{dx}(x)$ supposedly using the constant multiple rule.

The problem is that according to the constant multiple rule, $\dfrac{d}{dx}(8x)
$ should be rewritten as $8 \dfrac{d}{dx}(x)$ and not as $\dfrac{d}{dx}(8)\dfrac{d}{dx}(x)$ .

Therefore, Hannah made a mistake in this step.

6 0

4 years ago

Read 2 more answers

I need help urgent plz someone help me solved this problem! Can someone plz help I’m giving you 10 points! I need help plz help

Hitman42 [59]

Answer: L = 20.25

Step-by-step explanation:

$T=2\pi \sqrt{\dfrac{L}{32}}$

Given: T = 5, π = 22/7

$5=2\bigg(\dfrac{22}{7}\bigg)\sqrt{\dfrac{L}{32}}\\\\\\\dfrac{5}{2}\bigg(\dfrac{7}{22}\bigg)=\sqrt{\dfrac{L}{32}}\\\\\\\dfrac{35}{44}=\sqrt{\dfrac{L}{32}}\\\\\\\bigg(\dfrac{35}{44}\bigg)^2=\bigg(\sqrt{\dfrac{L}{32}}\bigg)^2\\\\\\\bigg(\dfrac{35}{44}\bigg)^2=\dfrac{L}{32}\\\\\\32\bigg(\dfrac{35}{44}\bigg)^2=L\\\\\\\large\boxed{20.25=L}$

8 0

3 years ago