Question

I don't really understand, please help!!

Answer 1

Step-by-step explanation:

In Triangle ICU,

Angle 2 = 180° - Angle 1 (Angles on a straight line)

CR = CU - RU

In Triangle ISR,

Angle 3 = 180° - Angle 4(Angles on a straight line)

SU = RS - RU

Angle 1 = Angle 4

Therefore, Angle 2 is equal to Angle 3

CU = RS

Therefore, CR is equal to SU

Triangle ICR and Triangle ISU

IC = IS

Angle 2 = Angle 3

CR = SU

Therefore, Triangle ICR and Triangle ISU are congruent (SAS congruency).

As the two triangles are congruent, Angle CIR = Angle SIU

Answer 2

Step-by-step explanation:

the proof is given above