Explanation:
Part A :-
m(a) , m(b) & m(c) when will get combined ; they will form a straight angle (180°) .
So,
m(a) + m(b) + m(c) = 180°
=> 3x + 5 + 5x - 18 + 7x - 2 = 180°
=> 15x - 15 = 180°
=> 15(x - 1) = 180°
=> x - 1 = 180 / 15
= 12°
=> x = 12 + 1
= 13°
Using the value of x gives the value of m(a) , m(b) & m(c) .
• m(a) = 3 × 13 + 5 = 39 + 5 = 44°
• m(b) = 5 × 13 - 18 = 65 - 18 = 47°
• m(c) = 7 × 13 - 2 = 91 - 2 = 89°
Part B :-
Complementary angles are the pair of angles whose sum is 90° . Here sum of m(a) & m(b) is
44 + 47 = 91°. Hence they are not complementary angles.