- Three of the five rays can each be called by only one name: OP,
ON, and OQ. Ray-names NOand NPare interchangeable, as
are ray names POand PN; each pair describes one ray each. NO
and NPdescribe a ray beginning at endpoint N and extending
infinitely through •O and •P. P Oand PNdescribe a ray beginning
at endpoint P and extending infinitely through •O and •N. - ONand OPare opposite rays. Of the five rays listed, they are the
only pair of opposite rays; they share an endpoint and extend
infinitely in opposite directions. - Angles have two sides, and unless a number is given to describe the
angle, angles can have two names. In our case ∠NOQ is the same
as ∠QON; ∠POQ is the same as ∠QOP; and ∠NOP is the same
as ∠PON (in case you missed this one, ∠NOP is a straight angle).
Letter O cannot by itself name any of these angles because all
three angles share •O as their vertex.
Set 5
- Two of the three rays can each be called by only one name: KL
and MN. LNand LMare interchangeable because they both
describe a ray beginning at endpoint L and extending infinitely
through •M and •N. - Two of the five angles can go by three different names. ∠KLM is
the same as ∠NLK and ∠MLK. ∠LKM is ∠MKL and also ∠K.
The other three angles can only go by two names each. ∠KMN is
∠NMK. ∠KML is ∠LMK. ∠LMN is ∠NML. Letter M cannot
by itself name any of these angles because all three angles share •M
as their vertex. - Line segments have two endpoints and can go by two names. It
makes no difference which endpoint comes first. LMis ML; MNis
NM; LNis NL; KMis MK; KLis LK.
501 Geometry Questions