Question

@mrnood
help

Answer 1

so you are obviously studying Pythagoras

you know that the formula is

a^2 + b^2 = c^2 where c is alwaysy the longest side

so assume the diagram is THIS:


write the formula with the numbers in from the diagram (a is still unknown...)

Answer 2

we are using cosine since there is adjacent and hypothenuse

Answer 3

no

this is not about trig functions -
it is about pythagoras

write the eqaution for a^2= ???

using the values from the diagram