http://prntscr.com/jgsx9s Geometry help
@Elsa213
it's blank
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we use the square area formula?
We find the area of the square then subtract out the area of the triangles that are not shaded.
Pretty easy to do, just hang on a minute.
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Okay, so basically, now we can easily find the area of the square, then find the areas of each triangle then perform the following calculation: \(\text{Area of Shaded Figure = Area of Square - Total Area of Unshaded Figures}\)
There is another way to do it. Let me post that.
ok
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Find the area of all those right triangles plus the area of the rectangle. Let's number them:
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we can do the first way xD
or the second
So we can find the area of each individual shaded figure to find the total shaded area. \(A_t = A_1 + A_2 + A_3 + A_4 + A_5 + A_6\)
You know the formulas for area of a triangle and area of a rectangle correct?
yes
we can do the first one
Actually, it's more efficient to do the second method.
Okay let's do that one lol
Actually, I was hoping that you would be inspired to try this on your own and post your attempt here using that formula I gave you above. See if you can find the areas of each small figure and post here: \(A_1 = ?\) \(A_2 = ?\) \(A_3 = ?\) \(A_4 = ?\) \(A_5 = ?\) \(A_6 = ?\)
ok
the base of the number 1 triangle is 5 and the height is 2 or 3?
It really doesn't matter to be honest. Either of the legs of the triangles can be considered base or height. As long as you're using the formula \(A = \dfrac{bh}{2}\) to calculate the area of the triangles
yeah I'm using that formula
how do I find the base and height of a triangle?
You measure the lengths of the segments for both legs of a right triangle. For example for Triangle 1, Leg 1 = | 1 - (-5)| = |1 + 5| = | 6 | = 6
leg 2 1 -(-3) = 1+3 = 4
You can also just count squares as well which would be easier to do mentally
did i do it correct?
with the second leg
If you count the squares, you will see that the measure of Leg 2 is just 3 units.
oh I thought i had to your math thing lol
the area is 12
my bad I was writing
The "math thing" I did is called absolute value. It's just the computation used to find the length of a segment on an xy plane. In this case, the leg occurs vertically, so you would write Length of Leg 2 = |\(y_2 - y_1| = | 0 - (-3)| = | 0 + 3| = | 3 | = 3\)
The area is 5 for triangle number 2
How did you get 5 for the area of triangle 2? Mind showing the work you did to come up with that?
Did you calculate the length of each leg first?
i counted the squares that had shade on them.
I would recommend that you count the squares rather than use the formula
i cant draw rip
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yeah that part is 5
I thought that side was the base cause the triangle is sideways
First count the vertical squares. You get 5 for that. Then count the horizontal squares. You get 2 for that
But yeah, it's five for the area.
ok lol wow
You're correct. So far we have: \(A_1 = 9\) \(A_2 = 5\)
A3= 3
A4=3
A5=2
Very good
RECTANLGE = 20
So \(A_6 = 20\) Okay, time to add them all up to get the total area.
So \(A_t \\= A_1 + A_2 + A_3 + A_4 + A_5 + A_6 \\= 9 + 5 + 3 + 3 + 2 + 20 \\= 14 + 6 + 22 \\= 20 + 22 \\= 42\)
The area of the first triangle is 9. Go back and calculate
oh i thought it was 12
Calculate it now and see what you get. Clearly the lengths of each leg are 6 and 3.
back my laptop wouldn't allow me to type nothing like it let me do nothing
10/10 grammar
yea it's 9
i put the height 4 on accident instead of 3
we did it!
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