Which of the following is the reason for line 2 in the proof

reflexive is the answer.

Step-by-step explanation:

A relation is reflexive (has the reflexive property) if it applies to itself.

Example: The relation ≤ on numbers is reflexive because for any number x we have x ≤ x.  Thus any relation is said to be reflexive if for any a, (a,a) satisfies this relation.

Here we have to prove congruence of two triangles.  We find that the two triangles taken for congruence has the base RS as common.

Thus RS being the side for both the triangles is  making the statement two sides of the triangle are equal .  This is due to reflexive property.

Hence the two triangles are congruent by SSS

54 kilometers per hour

step-by-step explanation:

according to rules:

1 km = 1000 meter

which means that 1 meter = 1/1000 km

1 hour = 3600 second [ as 1 hour = 60 min = 60 *60 seconds ]

which means that 1 second = 1/3600 hour

therefore, 1 kilometer/hour =

thus to convert 15 meter per second to kilometer per hour, we multiply 15 to 3.6 kilometer/hour.

15 meter/second=   which is the required answer.

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.