Answer: 200 units²
Step-by-step explanation:
The length at the bottom is 10 and all sides of the 15x15 square are all 15, therefore the bottom length is 25. This is because the shape consists of all squares, so the sides are all equal.
This means the area of the entire rectangle is 25x25=625 units².
The bottom left corner triangle is 10x10=100 units².
The bottom right corner triangle is 15x15=225 units².
The whole diagram is symmetrical due to it having squares (which are regular and all sides are equal), we can assume the square at the top right is also 10x10=100 units².
All that remains is to find the shaded region, by taking away the rest of the area of the squares from the total area.
225+100+100= 425 units²
625-425= 200 units²
