Option C. 110°
Step-by-step explanation:
As we can see in the figure attached AB and CD are the parallel lines and EC is the transverse.
y = 4x + 10 [ alternate angles ] --------(1)
and y + (6x + 20) = 180° [ supplementary angles ]---------(2)
By substituting the value of y from equation 1 to equation 2
(4x + 10) + (6x + 20) = 180
4x + 6x + 10 + 20 = 180
10x + 30 = 180
10x = 180 - 30 = 150
![x=\frac{150}{10}](/tpl/images/0398/2532/94a13.png)
x = 15
Now we can find the measurement of angle DAB
∠DAB = ∠A = 6x + 20
∠A = 6(15) + 20 = 90 + 20 = 110°
Option C is the correct option.
![In parallelogram abcd, find m∠a. a) 15° b) 70° c) 110° d) 200°](/tpl/images/0398/2532/06db9.jpg)