What is the missing reason in step 5 a. linear pair postulate b. givin c. definition of complementary angles d. congruent complements theorem

The Correct Answer On Edgen Is

A) Linear pair postulate.

(A) Linear pair postulate

Step-by-step explanation:

Given: AB intersects DE at point C.

To prove: ∠DCB≅∠ECA

Proof:

Statements                                                                   Reasons

1. AB intersects DE at point C.                                      given

2. ∠DCB and ∠BCE are a linear pair                       Definition of linear pair

3. ∠DCB is supplementary to ∠BCE                        Linear pair postulate

4. ∠BCE and ∠ECA are a linear pair                       Definition of linear pair

5. ∠BCE is supplementary to ∠ECA                       Linear pair postulate

Thus, from statement 2 and 5, we have

∠DCB+∠BCE=180° and ∠BCE+∠ECA=180°

⇒∠DCB+∠BCE=∠BCE+∠ECA

⇒∠DCB≅∠ECA

Hence proved

thus, option A is correct.

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.