Which is the definition of a rhombus? a quadrilateral with four right angles a quadrilateral with four congruent sides a quadrilateral with interior angles that sum to 360° a quadrilateral with two pairs of opposite congruent sides

x = 10.1

step-by-step explanation:

all of the angles of a tirangle add up to 180º

180 - 65 = 115 (since we already know the value of one angle)

(2x + 7) + (8x + 7) = 115

(combins like terms) 10x + 14 = 115

(isolate the variable subtract 14 from both sides): 10x = 101

(find the variable divide both sides by 10): x = 101/10

x = 10.1