What is the measure of angle A in the triangle?

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m∠A =

°



A triangle labeled ABC with angle A as parenthesis two X minus ten parenthesis degrees, angle B as seventy degrees and angle C as parenthesis X plus thirty parenthesis degrees

m∠A = 50

Step-by-step explanation:

Given "A triangle labeled ABC with angle A as parenthesis two X minus ten parenthesis degrees, angle B as seventy degrees and angle C as parenthesis X plus thirty parenthesis degrees",

it can be written out as:

m∠A = 2x-10

m∠B = 70

m∠C = x+30

As the sum of interior angles = 180 for a triangle,

2x-10+70+x+30=180

3x=180-30-70+10=90

x=30

m∠A = 2 (30) - 10 = 60-10

= 50

Angle A = 50

Step-by-step explanation:

We know the 3 angles of a triangle add to 180

A + B+C = 180

2x-10 + 70 + x+30 = 180

Combine like terms

3x+90 = 180

Subtract 90 from each side

3x+90-90=180-90

3x = 90

Divide by 3

3x/3 = 90/3

x = 30

We want to find angle A

Angle A = 2x-10

= 2 (30) - 10

= 60-10

= 50