Respuesta :

5.1^2 + 7.4^2 = c^2 (pyth. Theorem)
c = √5.1^2 + 7.4^2
c ≈ 8.98721
c = 9.0 ( corr. to nearest tenth)

Step-by-step explanation:

simple this is a right angle triangle, 90⁰, the red box inside the triangle indicates 90⁰

cos 90=7.4/c

c cos 90 = 7.4

c= 7.4/cos 90

c = 0