What is the value of x in trapezoid abcd

x=15

Step-by-step explanation:

Because CD║BA and BC≡AD,

Then: ∠B=∠A  and ∠C=∠D.

All for corners must add up to 360°:

∠A + ∠B + ∠C + ∠D = 360

2∠B + 2∠D = 360

2(3x) + 2(9x) = 360

6x + 18x = 360

24x = 360

x = 15

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

%40

step-by-step explanation: