+0  
 
0
25
2
avatar

The angles of a triangle are a, b and 50∘.

If the difference a - b is 40∘, then what is the value of a?

 

 Jul 29, 2020
 #1
avatar+26006 
+1

a-b = 40     so   b = a-40

 

then     a      +   a-40     + 50      = 180        solve for 'a'

 Jul 29, 2020
 #2
avatar+31 
+1

Solving using b

So we know that all angles in a triangle add up to 180°.

 

The equation we get is 50°+a+b=180°

 

Because there are two variables, we need to equations, and the other is already given. Which is a-b=40

 

We can use substitution and get 50°+(b+40°)+b=180°.

 

Just add and subtract a few things to get 2b=90°, and b=45°

 

We can take b back into the equation and get a=85°.

 

Solving using a

If we want to solve using a, we can substitute b=a-40 into the first equation.

 

We get 50°+2a-40°=180°. 2a=170° and a=85°.

 Jul 29, 2020

4 Online Users