Question

Please help me out please

Answer 1

Answer:

14.7

Step-by-step explanation:

a^2+b^2=c^2

15^2+b^2=21^2

225+b^2=441

subtract 441-225=216

square root of 216 = 14.6969384567

= 14.7

Answer 2

Answer:

x = 6$\sqrt{6}$

Step-by-step explanation:

Using Pythagoras' identity in the right triangle.

The square on the hypotenuse is equal to the sum of the squares on the other two sides, that is

x² + 15² = 21²

x² + 225 = 441 ( subtract 225 from both sides )

x² = 216 ( take the square root of both sides )

x = $\sqrt{216}$ = $\sqrt{36(6)}$ = $\sqrt{36}$ × $\sqrt{6}$ = 6$\sqrt{6}$