Which collection of three side lengths can be used to form a triangle?

40 cm, 30 cm, 75 cm

80 cm, 35 cm, 40 cm

40 cm, 65 cm, 30 cm

75 cm, 35 cm, 40 cm

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much

Astick 2 m long is placed vertically at point b. the top of the stick is in line with the top of a tree as seen from point a, which is 3 m from the stick and 30 m from the tree. how tall is the tree?

Solve the triangle. a = 21°, c = 105°, c = 5