Two straight lines intersect at point

MATHEMATICS · Multi-part · CBSE · Mathematics · Lines and Angles · Lines and Angles

Problem

O

. One of the angles is

(4a - 15)^{\circ}

. The angle vertically opposite to it is

(2b + 25)^{\circ}

. One of the angles adjacent to

(4a - 15)^{\circ}

(b + 35)^{\circ}

. (i) Find the values of

a

and

b

. (ii) Hence, find the measure of each of the four angles at

O