Question

If the m<1 + m<2 + m<3 = 180 and m<3 = 90, what property of equality justifies the conclusion that m<1 + m<2 = 90 ?

A. reflexive property
B. transitive property
C. symmetric property
D. subtraction property

btw, the < sign is actually an angle.

Answer 1

Review the properties here

http://www.regentsprep.org/Regents/math/geometry/GPB/theorems.htm

Answer 2

i dont get it

Answer 3

B.

Answer 4

Transitive says

If a = b and b = c, then a = c.

Answer 5

What happened from here
m1+m2+m3 = 180
m3-90
to here

m1+m2=90

Answer 6

so its ike if m<1 + m<2 + m<3 = 180, and m<3 = 90, then m<1 + m<2 = 90

Answer 7

right?

Answer 8

the leap?

Answer 9

>_> What mathematical operation happened between m1+m2+m3=180

to m1+m2=90

Answer 10

subtraction?

Answer 11

Something is missing is the second one. How did it go missing?

Correct! Subtraction

Answer 12

We subtracted m3 which is 90 on both sides.

Answer 13

So what property do we know of that involves subtracting things on both sides to keep the equation equal.

Answer 14

the subtraction property of equality