Question

the smallest angle of a triangle is one fifth the sum of the other two and the largest angle exceeds the sum of the other two by 20°. find the largest angle of the triangle.
(A) 100°
(B) 90°
(C) 120°
(D) 110°
[From chapter: Pairs of linear equations in two variable]
[Answer: (A) 100°]
Need steps!!! ​

Answer 1

Step-by-step explanation:

let smallest angle be s and largest angle is l respectively,third angle is 180-s-l

by given condition

s=(180°-(s+l)+l)/5

=(180°-s)/5

=36°-s/5

s=(5*36°)/6

s= 30 °

l=(s+180°-s-l)+20°

= (180°-l)+20°

=200°-l

2l=200°

l=200°/2

l=100°

third angle =180°-100°-30°

=50°

so largest (l) is 100°

smallest angle (s) is 30°