you can do this because angle NSO and RSQ are eqaul once you know x you will be able to solve all the other angles and subtract from 360 (the total angle) to find NSR.
Steps:
3x+11+5x-9 = 90
8x+2=90
<u>x= 11</u>
Solve 3(11)+11 = 44
add known angles:
44+90+90 = 224
360-224 = 136 degrees
We use concepts like <u>complimentary angles</u> and<u> vertical angle theroem</u>.
