Buzz
Guidance for solving exercise 5 on page 46 Mathematics Grade 4
Problem:
A rectangle has a length of a, and a width of b. Let P be the perimeter of the rectangle. We have the formula for calculating the perimeter of a rectangle:
P = (a + b) x 2 (a, b in the same unit)
Apply the formula above to calculate the perimeter of the rectangle, knowing:
a) a = 16cm, b = 12cm;
b) a = 45m, b = 15m.
Solution Method:
To solve this exercise, students only need to rely on the formula for the perimeter of a rectangle: P = (a + b) x 2, note: a, b in the same unit; substitute the given values into the formula and carefully calculate to find the result.
Answer:
a) For a = 16cm, b = 12cm, the perimeter of the rectangle is: P = (16 + 12) x 2 = 56 cm
b) For a = 45m, b = 15m, the perimeter of the rectangle is: P = (45 + 15) x 2 = 120 cm.
Section solving exercises page 46 Mathematics Grade 4 contains 5 exercises, after solving exercise 5 page 46 Mathematics Grade 4 textbook, students can continue to see hints and methods for Solving Exercise 1 Page 46 Mathematics Grade 4, Solving Exercise 2 Page 46 Mathematics Grade 4, Solving Exercise 3 Page 46 Mathematics Grade 4, and Solving Exercise 4 Page 46 Mathematics Grade 4 to improve their understanding of fourth-grade math.
