Question

How to solve this cause I was gone for 1/2 of my class and missed stuff.

Answer 1

the answer is 58°

a triangle can only have 180 degrees

we already know the measure of two angles

28+30= 58

because the third angle (let's call it x) for a a straight line (180°) with y, we know that
x + y =180

180-58 = 122°
x = 122°
180 - 122 = 58
y = 58°

Answer 2

• The interior angles of all triangles add to equal 180 degrees (triangle angle sum theorem)
• Supplementary angles add to equal 180 degrees

To find y, first find the measure of the third interior angle. We'll call it x.

The triangle angle sum theorem allows us to create an equation to find x. Set the interior angle values equal to 180 and solve.

180 = 28 + 30 + x

Add the constants.

180 = 58 + x

Subtract 58 from both sides.

122 = x

Now, ∠x (which we now know measures 122°) is supplementary to ∠y. Set them equal to 180 and solve for y.

180 = 122 + y

Subtract 122 from both sides.

58 = y

Answer:

m∠y = 58°