Question

1. which steps can be used to calculate the perimeter of shapes?

a. figure out the unknown angle of the triangle
b. add up the lengths of all the sides.
c. multiply the number of sides by the area
d. divide the area by the number of sides

Explanation:

The perimeter of a shape is defined as the total length around the shape. This is calculated by summing up the lengths of all its sides.

• Option a: Finding an unknown angle of a triangle is related to angle - measure concepts (using the angle - sum property of a triangle, \(180^{\circ}\) for a triangle) and not to perimeter.
• Option b: By the definition of perimeter, adding up the lengths of all the sides of a shape (whether it is a triangle, quadrilateral, etc.) gives the perimeter.
• Option c: Multiplying the number of sides by the area has no logical connection to the concept of perimeter. Area and perimeter are two different geometric measures.
• Option d: Dividing the area by the number of sides also has no relation to calculating the perimeter.

Answer:

B. Add up the lengths of all the sides.