So first of all this is a compound shape (any shape that is made up of two or more geometric shapes.)
The shapes shown is a RIGHT ANGLED TRIANGLE AND A SEMI CIRCLE.
u need to know the formulas to find the area of each shape.
Triangle: 1/2 x base x height
Semicircle: 1/2 x pi x radius squared
First lets find the area of the triangle: 1/2 x (10) x (30)= 150m
Semicircle: 1/2 x pi x (5)squared=30.27m to 2 decimal places
5 is the radius because 10 is the diameter
The radius is half the diameter.
Then add both areas to get 189.27m