14. Question wise,
In ΔRST,
∠R=2x+5
∠S=x+1
∠T=7x-16
we know,
∠R+∠S+∠T=180 [sum of 3 angles of a triangle is 180°]
2x+5+x+1+7x-16=180
10x-10=180
10(x-1)=180
x-1=18
x=19
so,
∠R=(2×19)+5=43
∠S=19+1=20
∠T=(7×19)-16=117
15. Question wise,
In ΔABC,
∠A=∠C-13
∠B=4∠C-11
we know,
∠A+∠B+∠C=180 [,,]
∠C-13+4∠C-11+∠C=180
6∠C-24=180
6∠C=180+24
∠C=204÷6=34
so,
∠A=34-13=21
∠B=(4×34)-11=125
16. Question wise,
In ΔJKL
∠K=∠J+9
∠L=2∠J-21
we know,
∠J+∠K+∠L=180
∠J+∠J+9+2∠J-21=180
4∠J-12=180
4∠J=180+12
∠J=192÷4=48
so,
∠K=48+9=57
∠L=(2×48)-21=75