Answer:
b. 10
Step-by-step explanation:
The triangles are all similar, so you have ...
hypotenuse/short side = x/4 = 25/x
Cross multiplying gives ...
x^2 = 100
x = 10 . . . . . . . take the square root
The answer is b) 10
We have to use the theorem of the cathetus or leg rule, that says "Each leg of the right triangle is the mean proportional between the hypotenuse and the part (projection) of the hypotenuse directly below the leg"
hypotenuse/leg =leg/part or b²= m*a
In this case,
hypotenuse= m
leg=x
part= 4
So,
x= √((21+4)*4)
x= √((25)*4)
x= √100
x= 10
