I know this isn't an ACTUAL learning question but this is urgent for I have an upcoming test...

how do you establish the formulas for areas of rectangles, triangles and parallelograms, and use these in problem-solving?

Look up these formulas in your text or on Google. The use depends upon the type of problem you have.

Establishing formulas for areas of rectangles, triangles, and parallelograms involves understanding the basic principles and properties of these shapes. Here are the step-by-step explanations:

Formulas for areas of rectangles:

Step 1: Understand the concept of a rectangle. A rectangle is a quadrilateral with four right angles (90 degrees each). Opposite sides are parallel and equal in length.

Step 2: Recall that the formula for the area of a rectangle is given by A = length x width, where A represents the area, length is the longer side, and width is the shorter side.

Step 3: Identify the dimensions of the rectangle (length and width) given in the problem or measure them if necessary.

Step 4: Substitute the length and width into the formula and calculate the area of the rectangle.

Formulas for areas of triangles:

Step 1: Understand the concept of a triangle. A triangle is a polygon with three sides and three angles. The area is based on the base and height of the triangle.

Step 2: Recall that the formula for the area of a triangle is given by A = (base x height) / 2, where A represents the area, base is the length of the base of the triangle, and height is the perpendicular distance from the base to the highest point of the triangle.

Step 3: Identify the dimensions of the triangle (base and height) given in the problem or measure them if necessary.

Step 4: Substitute the base and height into the formula and calculate the area of the triangle.

Formulas for areas of parallelograms:

Step 1: Understand the concept of a parallelogram. A parallelogram is a quadrilateral with opposite sides parallel and equal in length.

Step 2: Recall that the formula for the area of a parallelogram is given by A = base x height, where A represents the area, base is the length of the base of the parallelogram, and height is the perpendicular distance between the base and the opposite side.

Step 3: Identify the dimensions of the parallelogram (base and height) given in the problem or measure them if necessary.

Step 4: Substitute the base and height into the formula and calculate the area of the parallelogram.

Using these formulas in problem-solving:

Step 1: Read the problem carefully and identify the shape given (rectangle, triangle, or parallelogram).

Step 2: Determine which formula is appropriate for finding the area based on the given shape.

Step 3: Substitute the given dimensions into the formula.

Step 4: Perform the necessary calculations to find the area.

Step 5: Make sure to include the correct units, as area is typically measured in square units.

By following these step-by-step instructions, you should be able to establish the formulas for finding areas of rectangles, triangles, and parallelograms, as well as use these formulas to solve problems related to these shapes. Good luck with your upcoming test!

To establish the formulas for areas of rectangles, triangles, and parallelograms, you need to understand the basic concepts and properties of these shapes.

1. Rectangle:
The area of a rectangle is calculated by multiplying its length (l) by its width (w).
Area = l × w

2. Triangle:
The area of a triangle can be calculated by multiplying its base (b) by its height (h) and then dividing the result by 2.
Area = (b × h) / 2

3. Parallelogram:
The area of a parallelogram can also be calculated by multiplying its base (b) by its height (h).
Area = b × h

Once you understand these formulas, you can use them to solve problems involving these shapes. Here's an example problem:

Problem: Find the area of a rectangle with a length of 5 units and a width of 3 units.

Solution: To find the area of a rectangle, we can use the formula Area = Length × Width. Therefore, let's substitute the given values into the formula:
Area = 5 units × 3 units
Area = 15 square units

So, the area of the given rectangle is 15 square units.

Remember, when solving problems using these formulas, make sure to accurately identify the measurements required and apply the corresponding formula to obtain the correct result.