The proof shows that abcd is a rectangle. which of the following is the missing reason?

a. angle-side-angle postulate
b. side-angle-side postulate
c. angle-angle-side postulate
d. side-side-side postulate

Side-side-side postulate

Step-by-step explanation:

In the first statement, we are given that AC = BD (1){It is given}

Now, in the second statement, we are given that AB = DC (2){ Because the parallelogram has equal opposite sides}

Now, again we are given that AD = DA (3) {From the symmetric property}

Now, conditions (1), (2), and (3) are applicable to say that Δ ABD and Δ ACD are congruent.

Since there are three sides involved to say Δ ABD ≅ Δ ACD, so it is by Side-side-side postulate. (Answer)

hello from mrbilldoesmath!

answer:

25x^2 + 90x + 84

discussion:

mn(x) = m(n(x)) = m( 5x + 9) =

(5x + 9)^2 + 3 =>

25x^2 + 90x + 9^2 + 3 =

25x^2 + 90x + 84                 (as 9^2 = 9*9 = 81)

which is the second choice

regards,  

mrb

p.s.   i'll be on vacation from friday, dec 22 to jan 2, 2019. have a great new year!