Triangle abc is isosceles. what is the length of ? 11 23 40 60

An isosceles triangle is a triangle that has two of its sides equal and also two equal angles.

The length of line BC is 40

So,

line AB = x + 17

line BC = 2x - 6

equate the line

line AB = line BC

x + 17 = 2x - 6

x - 2x = -6 - 17

- x = - 23

x = 23

substitute x = 23 into

line AB = x + 17

= 23 + 17

= 40

line BC = 2x - 6

= 2(23) - 6

= 46 - 6

= 40

Therefore, the length of line BC is 40

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An isosceles triangle is a triangle that has 2 congruent/equal sides and 2 congruent angles.

Side AB and side BC are the same length (the red tick marks shows that the sides are congruent)

Since they are the same length, you can set them equal to each other

Side AB = Side BC

x + 17 = 2x - 6        Subtract x on both sides

17 = x - 6       Add 6 on both sides

23 = x

Now that you know "x", you can find the length of Side BC:

2x - 6      Plug in 23 for "x"

2(23) - 6

46 - 6 = 40

The length of BC is 40

  or  

sin y = 7/q

7 is the opposite side length, q is the hypotenuse

tan y = 7/r

7 is the opposite side length, r is the adjacent side length

using sohcahtoa ^^^^

cos y = adjacent/hypotenuse

cos y = r/q