Question

Angle A is an acute angle in a right triangle

Answer 1

Sin=opositeside/hyptonuse
cos=adjacentside/hyptoonse
try and draw a diagram
pretend we gots
acute angle is on left side
right angle is below obtuse angle

so sinA=7/25=left side/hypotonuse
so we need to find other side
pythagorean theorme

a²+b²=c²
7²+b²=25²
49+b²=625
b²=576
b=24

so

sinA=o/h
cosA=a/h

7=o
25=h
24=a

cosA=24/25

Answer 2

Cos= 24/25

7^2+24^2=25^2