Answer:
r = (ab)/(a+b)
Step-by-step explanation:
Consider the attached sketch. The diagram shows base b at the bottom and base a at the top. The height of the trapezoid must be twice the radius. The point where the slant side of the trapezoid is tangent to the inscribed circle divides that slant side into two parts: lengths (a-r) and (b-r). The sum of these lengths is the length of the slant side, which is the hypotenuse of a right triangle with one leg equal to 2r and the other leg equal to (b-a).
Using the Pythagorean theorem, we can write the relation ...
((a-r) +(b-r))^2 = (2r)^2 +(b -a)^2
a^2 +2ab +b^2 -4r(a+b) +4r^2 = 4r^2 +b^2 -2ab +a^2
-4r(a+b) = -4ab . . . . . . . . subtract common terms from both sides, also -2ab
r = ab/(a+b) . . . . . . . . . divide by the coefficient of r
The radius of the inscribed circle in a right trapezoid is r = ab/(a+b).
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The graph in the second attachment shows a trapezoid with the radius calculated as above.
Answer:
x = 2
Step-by-step explanation:
-4/5(-8x + 6) = 1 + 7 (distribute first)
6.4x -4.8 = 8 (add 4.8 on both sides)
6.4x = 12.8 (divide by 6.4)
x = 2
PLUG IN
-4/5(-8(2) + 6) = 1 + 7
-4/5(-16 + 6) = 8
-4/5(-10) = 8
8 = 8
Answer:
Length of the room is 180 ft
Step-by-step explanation:
We have a rectangular room with dimensions:
width = 70 ft and length "x" (unknown)
Perimeter of a rectangle is 2*w + 2*x and according to problem statement 500 ft of lights will fit exactly in room perimeter then:
2*70 + 2*x = 500
140 + 2*x = 500
2*x = 500 - 140
2*x = 360
x = 360/2
x = 180 ft
Answer:
x-intercept ⇨ -1/3
y-intercept ⇨ 1
Step-by-step explanation:
⟺ Finding the x-intercept, substitute y = 0
Move 1 to subtract the another side.
Then move 3 to divide -1, leaving only x as a subject since we want to find the x-intercept.
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⟺ Finding the y-intercept, substitute x = 0
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Tips:
Here's the tips about finding the intercepts of the graph.
⟺ For x-intercept, It's like solving an equation to find the x-term.
⟺ For y-intercept, It's like using the constant to answer.
As for y = mx+b where m = slope and b = y-intercept.
For a linear function, It's not necessary to substitute x = 0 just to find y-intercept as we can answer the constant as our y-intercept.
