Someone help plss :))

X+(x+70)+(x+20)=180° [ANGLE SUM PROPERTY OF A TRIANGLE]
= 3x+90= 180
= 3x= 90
= x= 30

So m angle R is x+20=30+20= 50°

The answer is thus 50°

The perimeter of a shape is the length of all the sides. therefore, you could either use the equation s+s+s+s, or s*4.