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Mathematics 21 Online
OpenStudy (anonymous):

Use π = 3.14. Determine the area and perimeter of the figures below. (Use π = 3.14. Round your answers to two decimal places.) (a) Assume that a = 8 m.

OpenStudy (anonymous):

OpenStudy (anonymous):

@DelTaVsPi

OpenStudy (anonymous):

okay, let me have a look at this :)

OpenStudy (anonymous):

thanks

OpenStudy (anonymous):

Okay, so this image is composed of two smaller shapes, a semi-circle and a triangle :)

OpenStudy (anonymous):

So lets solve the area first :) Because I like area questions haha XD

OpenStudy (anonymous):

it sure is

OpenStudy (anonymous):

lets do it

OpenStudy (anonymous):

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OpenStudy (anonymous):

I'm going to split this into two separate areas, like for example Area 1 and Area 2

OpenStudy (anonymous):

First we are going to solve for the semi circle first :)

OpenStudy (anonymous):

now, like always, we need to interpret carefully about the shape ! The semi-circle is composed of 180 degrees since it is half a circle

OpenStudy (anonymous):

Thus the formula is \[A = \frac{ \theta }{ 360 }\times \pi \times r^2\]

OpenStudy (anonymous):

Since "8" is the diameter --> the radius is half of 8, so it is 4. now 180/360 = 1/2 Sooo... A = 1/2 x Pi x (4) = 25.1327 Units^2

OpenStudy (anonymous):

So this will be Area 1

OpenStudy (anonymous):

Now we can solve for Area 2

OpenStudy (anonymous):

awesome!

OpenStudy (anonymous):

The area of the triangle is\[A = \frac{ 1 }{ 2 }\times Length \times height\]

OpenStudy (anonymous):

A = 1/2 x 8 x 8 = 32 units squared

OpenStudy (anonymous):

Okay the "Total Area" is given by A = Area 1 + Area 2 = 25.1327 + 32 = 57.1327 Units squared

OpenStudy (anonymous):

Okay cool, so now Area is completed, how do you feel about it?

OpenStudy (anonymous):

so is that area all togethers answer?

OpenStudy (anonymous):

Yeap that sounds about right!

OpenStudy (anonymous):

We can move onto findign the perimeter, once you are ready

OpenStudy (anonymous):

it says thats wrong

OpenStudy (anonymous):

Hmmm... let me check

OpenStudy (anonymous):

okay

OpenStudy (anonymous):

Hmm.. I'm not entirely sure where I could have gone wrong for the Area.

OpenStudy (anonymous):

We could move onto solving the Perimeter, we can get back to find the area later :)

OpenStudy (anonymous):

okay sounds good

OpenStudy (anonymous):

The perimeter of a semicircle is given by \[P = \frac{ 1 }{ 2 }\times 2\pi \times r\]

OpenStudy (anonymous):

r = 4 So -> P = 1/2 x 2(Pi) x (4) = 12.566 Units

OpenStudy (anonymous):

This will be perimeter 1

OpenStudy (anonymous):

Now we can solve for Perimeter 2

OpenStudy (anonymous):

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