first of all, find the area of the rectangle as it is the easiest. So, do A = L x W.
A = 24 x 15 = 360ft²
Then find the area of half of the triangle. So, do A = 1/2 x b x h
The length of the base of the full triangle (aka top of the rectangle) is 24ft so since we are finding the area of half of the triangle all you have to do it half 24 (12). (also 1/2 is the same as 0.5)
So the equation for that would be A = 1/2 x b x h = 1/2 x 12 x 10 = 1/2 x 120 = 60
So now, to find the area of the whole triangle, times 60 by 2 (as both of the halves are the same) which gives you 120.
Finally, to find the area of the WHOLE shape, do 360ft² + 120ft² which gives you 480ft².
A tangent forms a right angle with the centre of circle at the point it touches the circumference. i.e. OAB = 90 degrees If AOB = 55 degrees, then ABO = 90 - 55 = 35 degrees