Please help me find how to solve . The area of one is 196 with a side length of 21 in , the other has a side length of 15in

Area =100 in^2

Step-by-step explanation:

scale factor of the triangles is :15/21=5/7

if two similar shape has a scale factor a/b then the area is a^2:b^2

area of first shape/area of second shape=5/7

x/196=(5)²/(7)²

49x=4900

x=4900/49=100

area=100

check: 100/196=25/49=a^2/b^2

i hope it is right

idk

step-by-step explanation:

i don't know