Perimeter and Area of a Non-Standard Polygon

u07_l2_t2_we3 Perimeter and Area of a Non-Standard Polygon

Find the area and the perimeter of the polygon

so lets start with the area first

so the area of this polygon

and there's kind of two parts to this

first you have this part that's kind of rectangular

or it is rectangular

this part right over here

and that area is pretty straightforward

it's just going to be base times height

so the area's going to be 8 times 4

8 times 4 for the rectangular part

and then we have this triangular part up here

so we have this area up here

and for a triangle this area is base times height times 1/2

that actually makes a lot of sense

because you just multiply base times height

you would get this entire area

you get the area of the entire rectangle

and you see that the triangle is exactly half of it

if you took this part of the triangle

and you flip it over, you'd fill up that space

and you took this part of the triangle

and you flip it over, you'd fill up that space

so the triangle's area is half of

the triangle's base times the triangle's height

so plus 1/2 times the triangles base which is 8 inches

and the triangles height which is 4 inches.

so let us calculate it this gives us

it is not 4, triangles height is 3, so let us go back

and calculate it area = 32 + 1/2 * 8*3 = 32 + 12 = 44

area of the figure is 44

now let us do the perimeter.We need to figure out the

sum of the sides. If we need to put a fence

what is the length that we need to cover

so the perimeter = 8+4+5+5+4 =26 inches

Let me get the unit right, here we are multiplying

8 inches by 4 inches we get 32 square inches and

here we multiply 8 inches by 3 inches we get 24 square inches

divide by 2 we get 12 square inches.

area = 44 square inches, perimeter is 26 inches

area is two dimensional and perimeter is one dimensional