Answer:
The first angle is [tex]70^{o}[/tex].
Step-by-step explanation:
Let the measure of the second angle be represented by [tex]x^{o}[/tex].
Thus, the first angle = [tex](3x+10)^{o}[/tex]
Third angle = [tex]90^{o}[/tex]
Sum of angles in a triangle = [tex]180^{o}[/tex]
So that;
[tex]x^{o}[/tex] + [tex](3x+10)^{o}[/tex] + 90 = [tex]180^{o}[/tex]
[tex]x^{o}[/tex] + [tex]3x^{o}[/tex] + [tex]100^{o}[/tex] = [tex]180^{o}[/tex]
[tex]4x^{o}[/tex] = [tex]180^{o}[/tex] - [tex]100^{o}[/tex]
[tex]4x^{o}[/tex] = [tex]80^{o}[/tex]
divide both sides by 4 to have;
[tex]x^{o}[/tex] = [tex]20^{o}[/tex]
The first angle = [tex](3x+10)^{o}[/tex]
= ( 3 x 20 + 10)
= 60 + 10
= [tex]70^{o}[/tex]
Therefore, the first angle is [tex]70^{o}[/tex].
