2. Tyler has written an incorrect proof to show that quadrilateral ABCD is a parallelogram. He knows segments AB and DC are congruent. He also knows
angles ABC and ADC are congruent. Find the mistake in his proof.
Segment AC is congruent to itself, so triangle ABC is congruent to triangle ADC by
Side-Angle-Side Triangle Congruence Theorem. Since the triangles are congruent, so
are the corresponding parts, and so angle DAC is congruent to ACB. In
quadrilateral ABCD, AB is congruent to CD and AD is parallel to CB. Since AD is
parallel to CB, alternate interior angles DAC and BCA are congruent. Since
alternate interior angles are congruent, AB must be parallel to CD. Quadrilateral
ABCD must be a parallelogram since both pairs of opposite sides are parallel.
А
B
D
C

-12 > a

step-by-step explanation:

-11 > 1 + a

subtract 1 from each side

-11-1 > 1-1+a

-12 > a

2

step-by-step explanation:

step-by-step explanation:

part a. the differences are decreasing, so we know the sequence is not arithmetic. the ratios are constant (=3/4), so we know the sequence is geometric.

part b. from part a, we know the common ratio is 3/4, so each term is 3/4 of the one before. the initial term is the number of gallons at h=1.

g[h] = (3/4)·g[h-1]

g[1] = 384 . . . . initial value required for a recursive definition

part c. the general formula for a geometric sequence is

a[n] = a[1]·r^(n-1)

we have a[1] = 384, r = 3/4, and the term number given by h. the formula that follows is

g[h] = 384·(3/4)^(h-1)

part d. filling in the value and doing the arithmetic, we have

g[12] = 384·(3/4)^11 ≈ 384·0.042235136 ≈ 16.2183 . . gallons

part e. each gallon is 4 quarts, so

16.2183 gal × 4 qt/gal = 64.8732 qt