Question

Triangle ABC is an isosceles triangle in which AB = AC. What is the perimeter of △ABC?

5 + square root of 10 units

3x square root of units

10 + square root of 10 units

15 units

Answer 1

Answer:
perimeter = 10 + √10 units

Step-by-step explanation:
First, we will need to get the length of each line using the distance formula which is as follows:
distance =
`\sqrt{( x_(2)- x_(1) )^2 + ( y_(2) - y_(1))^2 }`

1- length of AB:
AB =
`√((-1--1)^2+(1-6)^2)` = 5 units

2- length of AC
length of AC is the same as AB = 5 units

3- length of BC:
BC =
`√((2--1)^2+(2-1)^2)` = √10 units

Now, we can get the perimeter by adding the side lengths as follows:
perimeter = 5 + 5 + √10
perimeter = 10 + √10 units

Hope this helps :)