I need help with number 5, find the area, thank you

If f(x)=x^3 and g(x)=2x+7 when g(x)=-5

1) in triangle the, what is the measure of angle t (in degrees)? 2) in triangle bat, the measure of angle b is 66∘, and the measure of angle t is 77∘.what is the measure of the exterior angle at a (in degrees)?

Arectangular garden measures 5m by 7m. both dimensions are to be extended by the same amount so that the area of the garden is doubled. by how much should the dimensions increase, to the nearest tenth of a metre?