Easy
Medium
Hard
100
What is the perimeter of triangle ABC? 
125 cm
100
A rectangle has a length of 28 cm and a width smaller by 6 cm. Find the perimeter of the rectangle.
Solution:
The width is 28 - 6 = 22 cm
The perimeter is 2 × (28 + 22) = 2 × 50 = 100 cm
100
John builds a square with a side of 12 cm from some wire. If from the same wire, he builds a rectangle with a width of 6 cm, what is the length of the rectangle?
Solution:
If the side of the square is 12 cm, then its perimetеr will be 48 cm. We build the rectangle from the same wire, so it is the same perimetеr. Its width is 6 cm, so its length is (48-12) ÷ 2 = 36 ÷ 2 = 18 cm
200
The red triangle is equilateral with a side of 23 centimeters. Its perimeter is __________ cm.
69 см
200
An isosceles triangle has a perimetеr of 37 centimetres and its base has a length of 9 centimetres. Each of the other two sides has a length of _________ cm.
Solution:
The isosceles triangle has two equal sides. The sum of the equal sides is 37 - 9 = 28 cm. Thus, one of them is 28 ÷ 2 = 14 cm
200
What is the perimeter of the red figure?
Solution:
Because the white figure is a rectangle, the unknown sides of the red figure are 12 cm, 8cm, 6cm, 16 cm. Perimeter is 18 + 24 + (12 + 6) + (8 + 16) = 18 + 24 + 18 + 24 = 42 + 42 = 84 cm
300
Find the missing side if the perimeter of the triangle is 11 units. 
Solution
Answer = 11 - 3 - 3 = 5 units
300
A rectangle has a width of 19 cm and a length three times greater than its width. Its perimeter is ____ cm.
Solution:
The length is 19 × 3 = 57 cm.
The perimeter is 2 × (57 + 19) = 2 × 76 = 152 cm.
300
A park shaped like a rectangle has a length of 24 meters and a width of 18 meters. If trees are planted on its sides with gaps of 2 meters between them, how many trees are needed? 
The perimeter of the rectangle is 2 × (24 + 18) = 2 × 42 = 84 meters, so there will be 84 ÷ 2 = 42 trees.