Question

In triangleABC AB=AC and angle B is 2/5 of angle A Find the measure of angle A​

Answer 1

Step-by-step explanation:

It is given that ∠A+∠B=125

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…(1)

We know that the sum of all the angles in a triangle is 180

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.

So we can write it as

∠A+∠B+∠C=180

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By substituting ∠A+∠B=125

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in the above equation

125

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+∠C=180

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On further calculation

∠C=180

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−125

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By subtraction

∠C=55

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It is given that ∠A+∠C=113

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By substituting the value of ∠C

∠A+55

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=113

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On further calculation

∠A=113

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−55

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By subtraction

∠A=58

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By substituting ∠A=58

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in equation (1)

So we get

∠A+∠B=125

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58

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+∠B=125

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On further calculation

∠B=125

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−58

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By subtraction

∠B=67

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Therefore, ∠A=58

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,∠B=67

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and ∠C=55

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.