Answer:
C. 3,4,5.
Step-by-step explanation:
The longest side must be < the sum of the two shorter sides, otherwise, you can't connect the 3 sides to make a triangle. In A, you get a straight line 4 cm long when you connect them together. In B and D you can't connect them together.
sqrt(1 - 36/49) = +root(13)/7
sin^2t + cos^2t is identical to 1 for all t.
(6/7)^2 + cos^2t = 1
1 - 36/49 = cos^2t
hence plus/miuns sqrt(1 - 36/49) = cos(t)
since t is acute, the answer must be positive.
shown and pictured all work
