A triangle with a base of 5 inches a height of 4 inches.
Millie makes a placemat with a triangular pattern. Each triangle has a base of 5 inches and a height of 4 inches. Millie sews together a total of 42 triangles.

Each triangle has an area of inches2
The total area of the placemat is inches2

If your asking if your work is correct, its not.

Each triangle has an area of 10 inches

the total area of the placemat is 420 inches

Step-by-step explanation:

Formula for area of a triangle is b · h

-14

step-by-step explanation:

2x2 – 2(x+4)

=2x2-2（5+4）

=4-2×9

=4-18

=-14

-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