Can someone help me and give an explanation

Two triangles: left triangle with y degrees and 40 degrees and right triangle with x degrees.

1) Subtract 180 - 40 = 140 degrees. 140 degrees is the unknown angle of right triangle.

2) 140 + x + x = 180 (equation)

ANSWER: x = 20 DEGREES

1) With knowledge of x degrees being 20 degrees, the other same angle is 20 degrees, too.

2) Subtract 90 - 20 = 70 degrees. 70 degrees is the (third) undetermined angle

of left triangle.

2) 70 + 40 + y = 180

ANSWER: y = 70 DEGREES

Whew. Hope this helps you out, and let me know asap if you're confused on any part.

i would need to see the dot plot : )

make sure you have version 2.50

try looking in the very back of the book : )

step-by-step explanation:

you can download it here