Hey : please help no fake anwsers : I’ll mark you brainliest :3

A≈120.71

Step-by-step explanation:

320units²

Step-by-step explanation:

one half triangle

area =1/2bh

area of the triangle= 1/2*5*8

= 20units²

area of the octagon= 16*20

=320units²

16 semi triangle will make up the octagon full

I hope it work for you

-3

step-by-step explanation:

a drawing really does here:

so i draw the horizontal line y=2 and the vertical line x=-2 at this intersection i put b (this is where my right angle is going to be).   so point b is at (-2,2).   point a is 5 units long and is also on y=2 so this point has to be (3,2) or (-7,2) -doesn't matter i will go with (3,2).

now we know c is at (-2,y) we don't know the y yet bet we know that c is on x=-2.

we have the area of the triangle is .5bh=12.5

we know the base length is 5 (ab)

we have the height is (2-y) if you look at your

plug in

.5(5)(2-y)=12.5

solve for y to get the y-coordinate for c

2.5(2-y)=12.5

divide both sides by 2.5 giving:

2-y=5

now subtract 2 on both sides

-y=3

y=-3