In this case, we'll have to carry out several steps to find the solution.
Step 01:
data:
parallelogram diagram
Step 02:
geometry:
parallelogram:
a = 2.4
b = 9
sides:
QP = RS
7a = 2a + 12
7(2.4) = 2(2.4) + 12
16.8 = 16.8
===> true
angles:
∠Q + ∠R = 180°
(10b - 16)° + (9b + 25)° = 180°
(10(9) - 16) + (9(9)+ 25) = 180
90 - 16 + 81 + 25 = 180
180 = 180
===> true
That is the full solution.