Hi!
So to make life easier split the figure into 3 different shapes: 2 right triangles at the top and a rectangle.
Now the base of each triangle is half of 24 which is 12.
You have to find the height of the figure using the pythagorean theorem.
a^2+ b^2 = c^2
a^2 + 12^2 = 13^2
a^2 + 144 = 169
a ^2 = 25
a = 5
now find the area of one triangle
(b*h) / 2
5*12=60
60/2 = 30
now multiply by 2 to have the area of both triangles
both triangles are 60
now subtract 5 from 30 to find the side length for the rectangle
30-5 = 25
multiply 24 and 25
24*25 = 600
now add 600 and 60 to find the area of everything
660 is the area
hope this helps!