2 Simple Questions, I just forgot how to do them

[Guest]

In the given figure, if b = radical 7 and c= 7, find the value of a

In the figure triangle JKL is a right triangle with KM an altitude. If JK = 15 and JM = 5, find the value of JL.

 

[Gene]

You have b & c reversed in the drawing. After correcting:
a²+b²=c²
a²+(sqrt(7))²=7²
a²+7=49
a²=42
a=sqrt(42)


JM²+KM²=JK²
KM = sqrt(JK²-JM²)
Similar triangles
JK/KM = JL/KL = KL/LM