Answer: x = 5.9
Explanation:
Solve for the larger triangle first by using the Pythagorean theorem:
7^2 + b^2 = 10^2
b^2 = 100 - 49
b^2 = 51
b = sqrt(51) = 7.14
Next, we can use this new-found side to solve for x by, again, using the Pythagorean theorem:
4^2 + x^2 = 51 (51 refers to b = 7.14 which is squared)
x^2 = 51 - 16
x^2 = 35
x = sqrt(35) = 5.9 when rounded to the nearest tenth.