Question

Translate the scenario below to a linear equation, then solve.

The second angle of a triangle is double the first angle. The third angle is 40 less than the first angle. Find the three angles.

First angle=
Second angle=
Third angle=
​

Answer 1

Answer: x + 2x + x-40 = 180

First angle= 55º

Second angle= 110º

Third angle= 15º

​Step-by-step explanation: The sum of the angles of a triangle is 180º

Take the values given and use x as the unknown first angle. then create terms for the other two angles based on that:

The second angle of a triangle is double the first angle becomes 2x

The third angle is 40 less than the first angle becomes x-40

x + 2x + x-40 = 180 Solve by adding like terms . x + 2x + x = 4x

4x -40 = 180 Add 40 to both sides to "cancel" the -40 on the left

4x + 40 -40 = 180 + 40 becomes

4x = 220 Divide both sides by 4 to "cancel" the 4 on the left side

4x/4 = 220/4

x = 55 This is the first angle. Substitute 55 for the "x" in the original terms

2(55) = 110 The second angle

(55) -40 = 15 the third angle