If two triangles are similar, which pair of conditions must be true? their corresponding sides are congruent. their corresponding angles are congruent. their corresponding sides are proportional. their corresponding angles are not congruent.

B) Their corresponding angles are congruent.

C) Their corresponding sides are proportional.

Step-by-step explanation:

Here is the definition of similar triangles.

If the two triangles are similar, then their corresponding angles must be equal and the sides are in proportion.

For example:

ΔABC ≈ ΔDEF are similar, then

∠A ≅ ∠D

∠B ≅∠E

∠C ≅ ∠F

and

AB/DE = BC/EF = CA/FD = constant.

According to the above definition, the following statements are true.

B) Their corresponding angles are congruent.

C) Their corresponding sides are proportional.

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional

so, converting firstly the mixed fractions to improper fractions and then "adding".