Four interior angles of a pentagon are 90o – xo, 90o + xo, 110o -…

Four interior angles of a pentagon are 90^o – x^o, 90^o + x^o, 110^o – 2x^o, 110^o + 2x^o. Find the fifth interior angle

Correct Answer: Option D

Explanation

Let the fifth interior angle be y: sum of interior angle of a pentagon
= (2 x 5 – 4) x 90^o
= 6 x 90^o
= 540^o
(90 – x) + (90 + x) + (110 – 2x) + (110 + 2x) + y = 540^o
400^o + y = 540^o
y = 540 – 400^o
y = 140^o