Triangle XYZ is reflected across the y-axis to create triangle PQR (not shown). What is the measure, in degrees, of angle R

The measure of ∠R = 60°

Step-by-step explanation:

The given parameters are;

Triangle XYZ is reflected across the y-axis to create triangle PQR

The measure of ∠Y = 30°

Triangle XYZ = A right triangle

The measure of ∠X = 90°

Where we have;

The image of the preimage of vertex X = P

The image of the preimage of vertex Y = Q

The image of the preimage of vertex Z = R

Therefore, given that a reflection is a rigid transformation, we have;

The measure of ∠X = The measure of ∠P

The measure of ∠Y = The measure of ∠Q

The measure of ∠Z = The measure of ∠R

Given that the measure of ∠Y = 30° and the measure of ∠X = 90°

∠X +∠Y + ∠Z = 180° (angle summation of a triangle property

∴ The measure of ∠Z = 180° - (∠X + ∠Y)  = 180° - (90° + 30°) = 60°

Therefore;

The measure of ∠Z = 60° = The measure of ∠R

The measure of ∠R = 60°.

2. angles qrt and qst both measures 156 degrees.

step-by-step explanation:  

we have been given a diagram of a circle and we are told that measure of arc qvt is 156 degrees.  

we can see from our given diagram that angle qrt and angle qst subtends to arc qvt.

since we know that angles subtended by the same arc at the circumference are always equal.

by angle subtended by same arc theorem, measure of angle qrt and angle qst will be equal to the measure of arc qvt.

therefore, angles qrt and qst both measures 156 degrees and 2nd statement is the correct choice.