I'll talk you through it so you can see why it's true, and then
you can set up the 2-column proof on your own:
Look at the two pointy triangles, hanging down like moth-wings
on each side of 'OC'.
-- Their long sides are equal, OA = OB, because both of those lines
are radii of the big circle.
-- Their short sides are equal, OC = OC, because they're both the same line.
-- The angle between their long side and short side ... the two angles up at 'O',
are equal, because OC is the bisector of the whole angle there.
-- So now you have what I think you call 'SAS' ... two sides and the included angle of one triangle equal to two sides and the included angle of another triangle.
(When I was in high school geometry, this was not called 'SAS' ... the alphabet
did not extend as far as 'S' yet, and we had to call this congruence theorem
"broken arrow".)
These triangles are not congruent the way they are now, because one is
the mirror image of the other one. But if you folded the paper along 'OC',
or if you cut one triangle out and turn it over, it would exactly lie on top of
the other one, and they would be congruent.
So their angles at 'A' and at 'B' are also equal ... those are the angles that
you need to prove equal.
Answer:
10m x 15m
Step-by-step explanation:
You are given some information.
1. The area of the garden: A₁ = 150m²
2. The area of the path: A₂ = 186m²
3. The width of the path: 3m
If the garden has width w and length l, the area of the garden is:
(1) A₁ = l * w
The area of the path is given by:
(2) A₂ = 3l + 3l + 3w + 3w + 4*3*3 = 6l + 6w + 36
Multiplying (2) with l gives:
(3) A₂l = 6l² + 6lw + 36l
Replacing l*w in (3) with A₁ from (1):
(4) A₂l = 6l² + 6A₁ + 36l
Combining:
(5) 6l² + (36 - A₂)l +6A₁ = 0
Simplifying:
(6) l² - 25l + 150 = 0
This equation can be factored:
(7) (l - 10)*(l - 15) = 0
Solving for l we get 2 solutions:
l₁ = 10, l₂ = 15
Using (1) to find w:
w₁ = 15, w₂ = 10
The two solutions are equivalent. The garden has dimensions 10m and 15m.
At Gino's you pay $16 plus $8 per pizza.
At Venetian's you pay $24 plus $6 per pizza.
Let the number of pizzas be x.
At Gino's you pay 16 + 8x
At Venetian's you pay 24 + 6x
Set the two costs equal and solve for x to find out the number of pizzas for which both costs are the same.
16 + 8x = 24 + 6x
16 + 2x = 24
2x = 8
x = 4
Each place gives you a free pizza.
4 pizzas plus the free pizza equals 5 pizzas.
If you need 5 pizzas (including the free one), both parlors cost the same.
If you need fewer than 5 pizzas, use Gino's.
If you need more than 5 pizzas, use Venetian's.
Red to yellow.......7:3....added = 10
so 7/10 of the total students wore red and 3/10 of the total students wore yellow
and there are 300 total students...
7/10(300) = 2100/10 = 210 wore red
3/10(300) = 900/10 = 90 wore yellow
how many more wore red.....(210 - 90) = 120 more students wore red then yellow
The figure is a right angle
Complementary = sum of 90 degrees
35 + 2x - 5 = 90
30 + 2x = 90
2x = 60
Solution: x = 30
