Answer:see explanationStep-by-step explanation:Using Pythagoras' theorem, that isThe square on the hypotenuse of a right triangle is equal to the sum of the squares on the other two sides.Using x instead of ?(a)The hypotenuse is the side opposite the right angle, that is 74, thus24² + x² = 74²576 + x² = 5476 ( subtract 576 from both sides )x² = 4900 ( take the square root of both sides )[tex]\sqrt{x^{2} }[/tex] = [tex]\sqrt{4900}[/tex]x = 70----------------------------------------------------------------------(b)The hypotenuse x is the unknown side herex² = 40² + 40² = 1600 + 1600 = 3200Take the square root of both sides[tex]\sqrt{x^{2} }[/tex] = [tex]\sqrt{3200}[/tex] ≈ 56.6 ( nearest tenth )