Question

Isosceles triangle:

The class was given the following isosceles triangle and asked to solve for the variable. Your classmate shows the following steps but has solved the problem incorrectly. Find the error that was made and explain it. Then answer the problem correctly
problem:
40+x+x=180
2x=220
x=110 degrees
Explain the mistake made and correct work and answer.

Answer 1

40 + x + x = 180

<=> 40 + 2x = 180

<=> 2x = 180 - 40 (not 180 + 40 =220)

<=> 2x = 140

<=> x = 70 deg

Hope this helps!

:)