Angle SRT is undetermined by the question.
A diameter always subtends a right angle (Thales' Theorem, the first in geometry) so we can be assured SRU, STU, RUT and RST are right angles.
Answer:
<h3>4cm</h3>
Step-by-step explanation:

Answer: 20.5 units
Step-by-step explanation:
P=Perimeter
JI=3-(-3)
JI=3+3
JI=6
IK=7-1
IK=6
JK=(6^2+6^2)^1/2 ==> Distance Formula
JK=(36+36)^1/2
JK=(2*36)^1/2
JK=6(2)^1/2
P=JI+IK+JK
P=6+6+6(2)^1/2
P=12+6(2)^1/2
P=20.485 units
P=20.5 units