Question

Last question AB= ? thank you for the help!

Answer 1

Answer:

AB = 45

Step-by-step explanation:

If ΔABC is an isoceles triangle, then 2 sides are equal in length.

From the diagram, we can see that AC = BC (the dashes mean the sides are of equal length).

Therefore, equate AC and BC, then solve for x:

                                                 AC = BC

                                            3x + 9 = 4x + 4

Subtract 3x from both sides:      9 = x + 4

Subtract 4 from both sides:        5 = x

So x = 5

Now we know that x = 5, we can substitute this into the expression for AB to find AB:

   AB = 8x + 5

⇒ AB = (8 x 5) + 5

⇒ AB = 40 + 5

⇒ AB = 45