In the diagram, what is AC?

find the DB =  ; now find AD=AB-DB=21-15=6  .Then                AC=  

C

Step-by-step explanation:

Using Pythagoras' identity in both right triangles

To find BD

BD² + CD² = BC²

BD² + 8² = 17²

BD² + 64 = 289 ( subtract 64 from both sides )

BD² = 225 ( take the square root of both sides )

BD = = 15

Then

AD = AB - BD = 21 - 15 = 6

To find AC

AC² = AD² + CD²

AC² = 6² + 8² = 36 + 64 = 100 ( take the square root of both sides )

AC = = 10 → C

the correct answer is 5 6 and 7

correct answer:

b.(19,-2)