SOLUTION: the second angle of a triangle is 3 times as large as the first. the third angle is 75 degrees more than the first. find the measure of the smallest angle.
A)105
B)15
C)21
D)7
Algebra ->
Triangles
-> SOLUTION: the second angle of a triangle is 3 times as large as the first. the third angle is 75 degrees more than the first. find the measure of the smallest angle.
A)105
B)15
C)21
D)7
Log On
Question 223947: the second angle of a triangle is 3 times as large as the first. the third angle is 75 degrees more than the first. find the measure of the smallest angle.
A)105
B)15
C)21
D)75 Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! Let x = "the first angle
:
Write an equation for each statement
:
"the second angle of a triangle is 3 times as large as the first"
3x = the second angle
:
"the third angle is 75 degrees more than the first."
x + 75 = the third angle
:
find the measure of the smallest angle.
we know the 3 angle add up to 180, therefore
:
x + 3x + (x+75) = 180
:
x + 3x + x + 75 = 180
:
subtract 75 from both sides, add up the x's
5x = 180 - 75
:
5x = 105
:
divide both sides by 5
x =
x = 21
:
You should be able to find the other two angles, make sure all 3 add up to 180
