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ABC is isosceles. Angles B and C are congruent. If m∠B = (5x + 5)° and m∠C = (7x - 25)°, Find m∠A.

User Gagolews
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2 Answers

4 votes
Angle A is twenty degrees
User Pbanfi
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6.3k points
4 votes
If B and C are congruent they are equal, so:

5x+5=7x-25

-2x=-30

x=15

So B=C=(5(15)+5)=80°

Since the angles must sum to 180° for any triangle...

A=180-2(80)=20°

So angle A is 20°
User Bradrice
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