Question

find x and the indicated angle measurement

Answer 1

let's bear in mind that, the sum of all interior angles in a polygon is

180(n - 2),  n = number of sides in the polygon.

now, this is a PENTAgon, it has 5 sides, thus n = 5, so the sum of all interior angles is then, 180( 5 - 2) => 180(3) => 540°.

now let's add them up then.

$\bf 4x+71+68+70+70=540\implies 4x+279=540\implies \blacktriangleright 4x=261 \blacktriangleleft\\\\\\x=\cfrac{261}{4}\implies \blacktriangleright x=65.25 \blacktriangleleft$