Question

Can someone pls help me pls

Answer 1

13)

let assume # denotes angle signs

now

as sum of 3 angels in triangle is 180

#2 +#3 +#4 = 180

also

#1 + #4 = 180

so equating both equation

#2 +#3 + #4 = #1 + #4

#4 will be cancelled from both side then

#2 + #3 = #1

proved

14)

ratio is 1:3:5

so Alma adsed it wrong. it should be 9x in 2nd line.

correction

x + 3x + 5x = 180

9x = 180

x = 180/9 = 20

so 1st angle = x = 20

2nd angle = 3x = 3×20=60

3rd angel = 5x = 5×20 = 100