1. Find angle x in each figure:
As we know, in an isosceles triangle, two sides and the angles they make with the third side are equal.
and
the sum of angles of the triangle is equal to . So,
i)
ii)
iii)
iv)
v)
vi)
vii)
viii) As we know, the exterior angle is equal to the sum of opposite internal angles in a triangle. So,
ix)As we know when two lines are intersecting, the opposite angles are equal. So