Which is a description of an undefined term?

the distance along a line segment is the number of units between two points.

perpendicular lines are lines that intersect at a right angle.

a ray extends infinitely in one direction from an endpoint.

an angle is the figure formed by the intersection of two rays at a common endpoint

Which is a description of an undefined term?

The distance along a line segment is the number of units between two points.
Perpendicular lines are lines that intersect at a right angle.
A ray extends infinitely in one direction from an endpoint. 
An angle is the figure formed by the intersection of two rays at a common endpoint

The description of an undefined term is A ray extends infinitely in one direction from an endpoint. 

option a, c,d are correct.

step-by-step explanation:

from the given figure, it is given that z is equidistant from the sides of the triangle rst, then from triangle tzb and triangle szb, we have

tz=sz(given)

bz=zb(common)

therefore, by rhs rule,δtzb ≅δszb

by cpctc, sz≅tz

also, from δctz and δasz,

tz=sz(given)

∠tcz=∠saz(90°)

by rhs rule, δctz ≅ δasz, therefore by cpctc, ∠ctz≅∠asz

also,from δasz and δzsb,

zs=sz(common)

∠zbs=∠saz=90°

by rhs rule, δasz ≅δzsb, therefore, by cpctc, ∠asz≅∠zsb

hence, option a, c,d are correct.

the first one is x^2+2x+2

the second one is x^2+4

the last one is x^2-4x+8