The perimeter of the rectangle is 36 cm. The sum of the lengths of its three sides is 25 cm. What is the area of this rectangle.
| January 5, 2021 | education
A rectangle has equal opposite sides. The perimeter is determined by the formula: P = 2a + 2b. According to the condition of the assignment, its value is 36 cm, and the sum of 3 sides = 25 cm.Let’s make a system of equations:
2a + 2b = 36,
2a + b = 25.
Let us express 2a through the second: 2a = 25 – b, substitute it into the first:
25 – b + 2b = 36,
b = 36 – 25 = 11 – length.
2a = 25 – 11 = 14,
a = 14: 2 = 7 cm – width.
S = 7 * 11 = 77 cm².
One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.
