491.57 cm^2
First find the area of the triangle and then the area of the rectangle and add them together.
To find the area of the triangle:
We know that the triangle is an isosceles triangle, so we need to use the side lengths (26) and the base length (10). We need to use Heron’s formula which is s = (a+b+c)/2.
So, (26+26+10) = 62
62/2= 31
Now we plug 31 into the equation for area
Area = square root of (s× (s- a) x (S -b) x (s - c)
s = 31, a = 26, b = 26, c = 10
31 x (31- 26) x (31 - 26) x (31 - 10)
31 x 5 x 5 x 21 = 16,275
Area ≈ 127.57
Area of the rectangle:
26 x 14 = 364
364 + 127.57 = 491.57
I would check my work on your own just to make sure, but I think the steps are right.