You got the b part wrong. It would be 4B+4C/2=4D
Answer:
k = 10
Step-by-step explanation:
The triangles angels added up must equal 180 degrees, and the top angle is 65 degrees by the 180 degree rule.
So 10k + 15 must equal the remaining 115
subtract 15 from each side and you get 10k = 100
divide each each by 10 and you get the answer of k = 10