Answer:
1.
cos ∅=b/h=24/25
:.b=24
h=25
by using Pythagoras law
h²=p²+b²
25²=p²+24²
p²=25²-24²
p=√7²=7
now
sin ∅=P/h=7/25
tan∅=p/b=7/24
2.cos ∅ is your answer
sec∅-sin∅tan∅
1/cos∅-sin²/cos∅
(1-sin²∅)/cos∅
cos²∅/cos∅
cos∅
3.
tan²∅-sec²x
sin²∅/cos²∅-¹/cos²∅
(sin²∅-1)/cos²∅