Respuesta :

The interior angles of a parallelogram will always equal 360. The interior angles of a triangle are 180 if it is a equilateral triangle then the angles are 60 degrees each. You know 2 sides of parallelogram. The 100 degree and 90 degree. You can find the one opposing the x because it’s on a straight line and a straight line is 180 degrees if a triangle is 60 degree angle then the opposing angle to complete the straight line must be 180-60 so you get 120. You now know 3 sides. 120, 90 and 100
They should add up to be 360 so you can set up an equation like so
120+90+100+x=360
And x = 50

Answer:

x = 50°

Step-by-step explanation:

The triangle has 3 congruent sides and is therefore equilateral.

The 3 angles are then congruent, each 60°

The left angle in the quadrilateral is adjacent to 60° of the triangle

180° - 60° = 120° ← angle inside quadrilateral

The sum of the interior angles of a quadrilateral = 360°

Subtract the sum of the angles from 360° for x

x = 360° - (120 + 90 + 100)° = 360° - 310° = 50°