9.5 Solve geometry applications: circles and irregular figures  (Page 3/5)

Solution

We can break this irregular figure into a triangle and rectangle. The area of the figure will be the sum of the areas of triangle and rectangle.

The rectangle has a length of $8$ units and a width of $4$ units.

We need to find the base and height of the triangle.

Since both sides of the rectangle are $4,$ the vertical side of the triangle is $3$ , which is $7-4$ .

The length of the rectangle is $8,$ so the base of the triangle will be $3$ , which is $8-4$ .

Now we can add the areas to find the area of the irregular figure.

The area of the figure is $36.5$ square units.

Solution

We will break the figure into a rectangle and two semi-circles. The area of the figure will be the sum of the areas of the rectangle and the semicircles.

The rectangle has a length of $105$ m and a width of $68$ m. The semi-circles have a diameter of $68$ m, so each has a radius of $34$ m.