The question is incomplete. Here is the complete question.
m∠J and m∠Kare base angles of an isosceles trapezoid JKLM.
If m∠J = 18x + 8, and m∠M = 11x + 15 , find m∠K.
A. 1
B. 154
C. 77
D. 26
Answer: B. m∠K = 154
Step-by-step explanation: Isosceles trapezoid is a parallelogram with two parallel sides, called Base, and two non-parallel sides that have the same measure.
Related to internal angles, angles of the base are equal and opposite angles are supplementary.
In trapezoid JKLM, m∠J and m∠M are base angles, so they are equal:
18x + 8 = 11x + 15
7x = 7
x = 1
Now, m∠K is opposite so, they are supplementary, which means their sum results in 180°:
m∠J = 18(1) + 8
m∠J = 26
m∠K + m∠J = 180
m∠K + 26 = 180
m∠K = 154
The angle m∠K is 154°