Question

What is the value of x?

Answer 1

42.5

Explanation:

Side EF = 40

Side DF = 40

that means it is a equilateral triangle so:

Angle ∠E = Angle ∠D (which is x)

(180-95) / 2

= 42.5

Answer 2

`x=42.5^o`

Explanation:

Notice that this is an isosceles triangle, so the angles opposite to the sides of equal length (40 units) must be equal. That means that angleD = angleE

Then using the rule for addition of interior angles of a triangle equal to 180, we can write:

angleD + angleE + angleF = 180 degrees

x + x + 95 = 180

2 x = 180-95

2 x = 85

x = 85/ 2

x = 42.5 degrees