Question

PLEASE HELP I GIVE THANKS

Answer 1

Well for 3.  you use the Pythagorean theorem to say that 28^2 - 18^2= x^2 so 21.4  and for 4. the Pythagorean theorem says a^2 + b^2 = c^2 with c being the hypotenuse of any right triangle so the sums of the two smaller squares make the sum of the larger square making the answer b