Question

HELP ASAP!! NO WORK NEED!!Triangle ABC is a right triangle. Which equation can be used to find the value of x? CHECK ALL THAT APPLY

Answer 1

The exterior angle equals the sum of two interior opposite angles

x + 90 = 2x + 40

Sum of all interior angles = 180

x + 90 + (x - 10) = 180

Answers:

x + 90 + (x - 10) = 180

x + 90 = 2x + 40

Answer 2

The triangle angles add to 180, so

x+90+(x-10)=180 works, CHECK

2x = 100

x=50

The second one doesn't make much sense; it could be made to work without the 180 or with two 180s which cancel. It doesn't check at x=50 so we don't check either.

The third one 2x+80=180. That gives the right answer, x=50, but I don't see how to read it off the diagram so I'm not going to check it.

x+90=2x+40 makes sense; they're both the supplement to BCA. CHECK

The last one doesn't check for x=50 so we don't check it.