Answer :
Answer:
x = 30 Quadrilateral
x = 20 Triangle
Step-by-step explanation:
Quadrilateral
A quadrilateral has a sum of 360 degrees for its interior angles.
So
x + 2x + 4x + 5x = 360 Find the sum of the 4 angles
12x = 360 Divide by 12
12x = 360/12
x = 30 Answer
Triangle
A triangle has an interior angle sum of 180 degrees.
2x + 5x + (x + 20) = 180 Remove the brackets
2x + 5x + x + 20 = 180 Add the angles
8x + 20 = 180 /subtract 20 from both sides
8x = 180 - 20
8x = 160 Divide by 8
x = 160/8
x = 20