How many degrees is angle x?

A normal-level "Angle" problem."Equal sides mean equal angles." That one sentence solves every isosceles-triangle problem.

GivenAB and AC have the same length (isosceles triangle)

Hints

Sides AB and AC are the same length (see the marks). In a triangle with two equal sides, the two base angles are equal too. So bottom-left and bottom-right are the same size.
Cut off the three angles and gather them at one point below.
Laid out they make a straight line, i.e. 180°. It consists of "one apex angle" and "two equal x's".
Removing the 40° apex from 180° leaves 140°. That is two x's.
Two x's make 140°, so 140 ÷ 2 is the answer.

Answer 70°