Answer:
y=84
first : 84+13=97
second : 84+15=99
third : 84+23=107
fourth: 84+29=113
fifth : 84+40 =124
97+99+107+113+124 = 540
Step-by-step explanation:
sum of interior angles of a pentagon=540 degreas
y+13+y+15+y+23+y+29+y+40=540
5y=540-(13+15+23+29+40)
y=84
first : 84+13=97
second : 84+15=99
third : 84+23=107
fourth: 84+29=113
fifth : 84+40 =124
97+99+107+113+124 = 540