Answer:
√61
Explanation:
using Pythagorean theorem,
h²+b²=hy²
h²+b²=hy²4²+2²=hy²
h²+b²=hy²4²+2²=hy²16+4=20
h²+b²=hy²4²+2²=hy²16+4=20hy²=20
therefore in radical form, Hy=√20
with the same theorem;
h²= hy²-b²
b² is initially given as (√20)²
hy² is given as 9²
h²=9²-(√20)²
h²=81-20
h²=61
h=√61