<h3>Answer:
122 degrees</h3>
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Explanation:
Angle BAC can be shortened to "angle A" since the letter A is in the middle.
Angle BCA can be shortened to "angle C" for similar reasoning.
We're told that angles A and C are base angles. For any isosceles triangle, the base angles are congruent
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Let's use this fact to solve for x.
angle A = angle C
7x+1 = 5x+9
7x-5x = 9-1
2x = 8
x = 8/2
x = 4
Once we know what x is, we can find each base angle
- angle A = 7x+1 = 7*4+1 = 28+1 = 29
- angle C = 5x+9 = 5*4+9 = 20+9 = 29
Both angles A and C are 29 degrees each, so this confirms we have the correct x value.
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The last step is to use the fact that all three angles of a triangle add to 180 degrees. This will help us find angle B, which is the vertex angle.
A+B+C = 180
29+B+29 = 180
B+58 = 180
B = 180-58
B = 122
The vertex angle is 122 degrees.
So we can say either angle B = 122, or we could say angle ABC = 122
"angle ABC" is the same as "angle CBA".
Answer with explanation:
Given:
In Δ DEF, ∠3=∠4.
To prove:→ DE=E F
Proof:
1. ∠3=∠4------[Given]
2. →∠1 and ∠ 3 are Supplementary to each other.
(a)⇒∠1 + ∠ 3=180°
→∠2 and ∠ 4 are also Supplementary to each other.
(b)⇒∠2 + ∠ 4=180°
--------------------[Exterior sides in opposite rays]
3. From 1 , a and b
⇒∠ 1 = ∠ 2-------[Two Angles Supplementary to equal Angles are equal to each other]
4. 
If two angles of a Triangle are equal , then side opposite to these angles are equal.
Answer:$88
Step-by-step explanation:
multiply 80 dollars by 10% then add that answer to 80 dollars and that gives you 88 dollars
The should be 158 ways, because 9*8+8*7+6*5=158.
