Answer:
E) 36 ft²
Explanation:
Formulae
- Area of a triangle = 1/2 x base x height
- Area of a rectangle = width x length
The shape is made up of 2 congruent triangles and 3 different rectangles.
Area of triangle = 1/2 x 3 x 4 = 6 ft²
Area of rectangle 1 = 2 x 4 = 8 ft²
Area of rectangle 2 = 2 x 3 = 6 ft²
To calculate the area of the 3rd triangle, we need to use Pythagoras' Theorem to determine the length of the hypotenuse of the right triangle.
a² + b² = c²
⇒ 3² + 4² = c²
⇒ 25 = c²
⇒ c = √(25)
⇒ c = 5 ft
Therefore, area of rectangle 3 = 2 x 5 = 10 ft²
Total Surface Area
Total SA = 2 triangles + rectangle 1 + rectangle 2 + rectangle 3
= (2 x 6) + 8 + 6 + 10
= 36 ft²