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).
_____
The graph in the second attachment shows a trapezoid with the radius calculated as above.
Y = 2x + 1
y = 2(-1) + 1
y= -2 + 1
y= -1
Answer:
Step-by-step explanation:
4/7 x + 70 cm^3 = 3/4 x Subtract 4/7 x from both sides
3/4 x - 4/7 x = 70 cm^3 The lowest common denominator is 28

5x = 70*28
5x = 1960 Divide by 5
x = 1960/5
x = 392 cc
Answer:
3.66666666667
Step-by-step explanation:
If you multiply the number of batches he makes and the amount of grape juice he needs for every quart, you get and answer of 3.66666666667.
1/3 * 11= 3.66666666667
If you need to round the answer it would be 3.67