explain how to do this please!

Answer:
The area of figure = 600 cm ²
Step-by-step explanation:
Area of this figure = area of triangle + area of rectangle
Area of triangle = 1/2 × base × height
Area of rectangle = length× breadth
=> (1/2 × 20 × 20 ) + ( 20×20 )
=> 200 + 400
=> 600 cm²