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.
If two expressions have the same coefficients of the variable, then the variable can be any number
For the first choice
3(3r + 3) = 9r + 9 === 1st expression
6r + 6 2nd expression
If we equate them
9r + 9 = 6r + 6
If we solve the equation we will find just one value of r
9r + 9 - 6r = 6r - 6r + 6
3r + 9 = 6
3r + 9 - 9 = 6 - 9
3r = -3
r = -1
But in the other choices, the two expressions have the same coefficients of r
Then when we equate them they will cancel each other
Then r can be any value
Because it does not affect the equation