Question

Not entirely sure….some help please?

Answer 1

55°

Explanation:

The definition of an isosceles triangle is that there are two sides of equal length and one side of a different length. Because two sides have the same length, their respective angles have the same measure. For example, side BC goes with angle A; because it is the same length as side AB which goes with angle C, angles A and C are the same. Just set the angles equal to each other and begin solving an algebraic expression as shown here:

`3x+40=x+50\\3x-x+40 = x-x+50\\2x+40=50\\2x+40-40=50-40\\2x=10\\(2x)/(2) =(10)/(2) \\x=5`

Now that you know what x is equal to, plug it into angle A's equation.

`3(5)+40\\15+40\\55`

Angle A is equal to 55°