Answer:
D
Step-by-step explanation:
The total of the triangle is 360. So add 131 and 160 which gets 291. Then subtract 360 from 291 and get 69.
Answer:

Step-by-step explanation:
Given Equations:
Equation:1
Equation:2
Solving Equation:2 for the value of 'y'

Subtracting '5x' both sides:
Equation:3
Using substitution method: Put the value of 'y' in equation:1


Subtracting '51' both sides:

Putting the value of 'x' in equation:3


The values of 'x' and 'y' are:

Answer:
yes,it will be because. 12^2+16^2=20^2
144+256=400so,that it prove the two side of a sum is equal to opposite side.so,the the firm be a right angle.