Will give branliest if correct :)

15.71

Step-by-step explanation: I did It on a peice of paper and it's a mess so yeah

d. 145*2 is 290 than the total angle is 360 then minus 290 then divide by two

180°

step-by-step explanation:

sum of equilateral triangle=180°

< n=60°

< m=120°°[angle supplementary of equilateral angle]

< m+< r+< x=360°(sum of exterior angle of triangle)