Question

Two supplementary angles differ by 78° what are their measures

Answer 1

Supplementary angles sum = 180°

let

angle be = x

so the other angle = 180° - x

Given that

180° - x - x = 78°

180° - 2x = 78°

180° - 78° = 2x

102° = 2x

x = $\frac{102}{2}$

x = 51°

Answer 2

$\huge\blue{solution}$

sum of supplementary angles = 180°

difference supplementary angles = 78°

let the two angles be x and y.

equation 1 = x + y = 180°

equation 2 = x - y = 78°

putting the two equations, we get.

x + y = 180°

x - y = 78°

_________

2x = 258°

x = 129°

putting the value in the equation 1.

129°+ y = 180°

y = 180°-129°

y = 51°

thus ,the two angles are 129°and 51°.

${\huge{\overbrace{\underbrace{\green{thanks}}}}}$