Question

What is the value of x?
x = 55°
x = 60°
x = 70°
x = 110°

Answer 1

x = 55°

Explanation:

We have an isoceles triangle.

`70 + x + x = 180`

`70 + 2x = 180`

`2x = 110`

`x = 55`

So the base angles of this triangle measure 55 degrees.

Answer 2

○
`x` = 55°

Explanation:

As we can see in the diagram, ∠A and ∠C are equal and both have a measure of
`x`.

To find the value of
`x`, we have to use the triangle sum theorem:

`x` +
`x` + 70° = 180° [angles in a triangle add up to 180°]

⇒ 2
`x` + 70° = 180°

⇒ 2
`x` = 180° - 70° [subtracting 70° from both sides]

⇒ 2
`x` = 110

⇒
`x` =
`(110)/(2)` [dividing both sides by 2]

⇒
`x` = 55°