Answer:
Explanation:
I take it that the question is What is the value of x.
... Every triangle has a measure of 180o so that is what is on the right side of the equation.
... the Vertex of an isosceles triangle has a unique value. There is only one angle with a measure of 42.
... The Base angles are equal. And there are 2 of them.
Equation
2x + 3 + 2x + 3 + 42 = 180o
Solution
Combine like terms
2x + 2x + 3 + 3 + 42 = 180 Show the like terms as 1 term for the xs and 1 for the pure numbers on the left.
4x + 48 = 180 Subtract 48 from both sides
4x = 180 - 48 combine
4x = 132 Divide by 4
4x/4 = 132/4
x = 33
Answer
x = 33
2x + 3 = 2*33 + 3 = 69
So the three angles are
69 + 69 + 42
Check
69 + 69 + 42
138 + 42
180 as it should.