Can help anyone answer this?

Step-by-step explanation:

We can use basic angle relationships to find m∠1.

We know that the 130° angle and m∠D are supplementary. This means their angle measures add up to 180°. Since we know one, we can find m∠D by subtracting it from 180.

So m∠D is 50°.

We also know that all angles in a triangle add up to 180°. Since we know two out of the three, we can add the two and subtract from 180.

So m∠2 = 60°.

Again, m∠2 and m∠1 are supplementary. Since we know 1, we can find m∠1 by subtracting from 180.

So m∠1 is 120°.

Hope this helped!

Explanation:

Let y be the measure of the interior angle adjacent to the 130 degree exterior angle

y+130 = 180

y = 180-130

y = 50

Interior angle D is 50 degrees.

It adds to angle C getting 50+70 = 120, which is the measure of angle 1 due to the remote interior angle theorem.

We can see it if we let angle 2 be x

B+C+D = 180 ... interior angles of a triangle add to 180

x+70+50 = 180

x+120 = 180

x = 180-120

x = 60

angle B = 60

To find angle 1, we subtract this from 180, since

(angle1)+(angle2) = 180

(angle1)+(60) = 180

angle1 = 180-60

angle1 = 120

This leads to the same result as before.

proofs involving isosceles triangles often require special consideration because an isosceles triangle has several distinct properties that do not apply to normal triangles.(more about triangle types) therefore, when you are trying to prove that two triangles are congruent, and one or both triangles, are isosceles you have a few theorems that you can use to make your life easier.

step-by-step explanation:

an isosceles triangle has two congruent sides and two congruent angles. the congruent angles are called the base angles and the other angle is known as the vertex angle. ∠bac and ∠bca are the base angles of the triangle picture on the left. the vertex angle is ∠abc

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