Solve Exercise 4 on pages 144, 145 of Math textbook Grade 4

Guide to solve Exercise 4 on pages 144, 145 of Math textbook Grade 4

Problem statement:
The perimeter of the rectangle is 56m, length is 18m. Find the area of the rectangle.

Solution Method:
- Step 1: Calculate half the perimeter of the rectangle by dividing the perimeter by 2
- Step 2: Calculate the width of the rectangle by subtracting half the perimeter from the length
- Step 3: Calculate the area of the rectangle by multiplying the length by the width. 

Answer:
Half the perimeter of the rectangle :
           56 : 2 = 28 (m)
The width of the rectangle is:
           28 - 18 = 10 (m)
The area of the rectangle is:
          18 x 10 = 180 (cm²)
               Answer: 180cm²

Here is the solution guide for Exercise 4 on pages 144, 145 of Math textbook Grade 4 in the concentrated practice section. Additionally, this section also includes 2 other exercises: Solve Exercise 1 on pages 144, 145 of Math textbook Grade 4, Solve Exercise 2 on pages 144, 145 of Math textbook Grade 4, and Solve Exercise 3 on pages 144, 145 of Math textbook Grade 4. Let's check out the solutions for Grade 4 Math exercises on pages 144, 145 to excel in Mathematics Grade 4!