Can someone help me find the missing side length!

12

Step-by-step explanation

so what I did is I divided 15 by 5 to get 3 also 9 divided by 3 equals 3 to so you could of also done that.

then i multiplied to 4 x 3 to get the missing side length which equals 12

the answer is 12

Step-by-step explanation:

to find the length we us this formula a²+b²=c²

a²+b²=c²

a²+(9)²=(15)²

a²+81=225

a²=225-81

a²=144

a=√144

a= 12 unit

a mantle plume is an upwelling of abnormally hot rock within the earth's mantle. as the heads of mantle plumes can partly melt when they reach shallow depths, they are thought to be the cause of volcanic centers known as hotspots and probably also to have caused flood basalts.

step-by-step explanation: