Given a || b , and c is not parallel to a or b, which statements must be true?
Select each correct answer.
m∠8 = m∠9
m∠7 = m∠10
m∠4 = m∠8
m∠2 = m∠7

C. m∠4 = m∠8

D. m∠2 = m∠7

Step-by-step explanation:

Here, we use the principles of alternate angles, corresponding angles and vertically opposite angles to confirm which of the statements are true. Alternate angles are always equal, corresponding angles are equal, likewise vertically opposite angles.

From the given question, it was given that a is parallel to b. Thus, it can be observed and deduced that;

m∠4 = m∠8  (corresponding angles)

and

m∠2 = m∠3 (vertically opposite angles)

m∠3 = m∠7 (corresponding angles)

So that,

m∠2 = m∠7  

Thus in the question, statements C and D are true.

the answer is: d) o, f, and kr.

atomic radius of bromine (br) is 114 pm.

atomic radius of oxygen (o) is 73 pm.

atomic radius of fluorine (f) is 72 pm.

atomic radius of krypron (kr) is 112 pm.

the atomic radius of a chemical element is a measure of the size of its atom.

the atomic radius varies with increasing atomic number, but usually increases because of increasing of number of electrons.

the atomic radius decreases across the periods because an increasing number of protons, because greater attraction between the protons and electrons.