Answer:
a = 7, b = 
Step-by-step explanation:
Using the sine ratio in the left right triangle and the exact value
sin45° =
, then
sin45° =
=
=
( cross- multiply )
a ×
= 7
( divide both sides by
)
a = 7
--------------------------------------------------------
Using the tangent ratio in the right triangle on the right and the exact value
tan60° =
, then
tan60° =
=
=
=
( multiply both sides by b )
b ×
= 7 ( divide both sides by
)
b =
×
= 
Let us try and solve it analytically. We have that the side=x+3 together with the short side=s and the diagonal=x+4 satisfy the Pythagorean Theorem. Then we have that

. This yields

which yields s^2=2x+7, hence a) is the correct answer.
60............. what this doesn't make sense