Answer:This is an isosceles triangle (note that two of the side length has the same measurements). This means that their opposite angles will be the same measurement. (Meaning that the two angles that do NOT have numbers yet are both with the variable x). Also note that a triangle's angle measurements = 180°.Set the equation.x + x + 70 = 180First, simplify. Combine like terms.x + x + 70 = 180(x + x) + 70 = 1802x + 70 = 180Isolate the variable, x. Note the equal sign, what you do to one side, you do to the other. Remember to do the opposite of PEMDAS. *As a side note, remember that PEMDAS = ParenthesisExponents (& roots)MultiplicationDivisionAdditionSubtraction& is the order that you will answer the question.*First, subtract 70 from both sides.2x + 70 (-70) = 180 (-70)2x = 180 - 702x = 110Isolate the variable, x. Divide 2 from both sides.(2x)/2 = (110)/2x = 110/2x = 5555° is your answer for x.~