AB = 21 DC =3x
AD = y +7
BC = 2y
Quadrilateral ABCD is a parallelogrami
both pairs of opposite sides are
congruent. Show that quadrilateral ABCD is a
parallelogram by finding the lengths of the
opposite side pairs.

d) by the cross product property, ab^2 = bc multiplied by ad

step-by-step explanation:

we are given

in the given triangle abc

angle a is 90° and segment ad is perpendicular to segment bc

we can see that

triangle(abc) and triangle(abd) are similar because they have common side and same angle (90 degree)

so, triangles(abc) and abd are similar

since, they are similar

so, the ratio of their sides must be equal

we get

now, we can cross multiply

and we get

so, this could be step to prove it

is the anwser b. (-13)?

(−$11) ⋅ 12

deductions are subtracted and there are 12 months in a year