3rd grade geometry

Example

A rectangle has a perimeter of 52 ft. Its length is 15 ft. What is its width, in ft?

1. 52 − 2 × 15 = 22
2. 22 ÷ 2 = 11 ft

Answer: 11

Example

A quadrilateral has 4 equal sides and 4 right angles. What is it?

1. That describes a square.

Answer: square

Example

An L-shape is made by cutting a 5 cm by 3 cm rectangle from the corner of a 8 cm by 9 cm rectangle. What is the area of the L-shape, in cm²?

1. 8 × 9 = 72
2. 5 × 3 = 15
3. 72 − 15 = 57 cm²

Answer: 57

Example

Sam wants a rectangular vegetable patch with an area of 24 m². It must be 3 m wide. How long must it be?

1. 24 ÷ 3 = 8
2. 8 m

Answer: 8

Example

Rectangle A is 1 cm by 16 cm. Rectangle B is 2 cm by 8 cm. They have the same area. Which has the greater perimeter?

1. A: 2 × (1 + 16) = 34 cm
2. B: 2 × (2 + 8) = 20 cm
3. Rectangle A

Answer: Rectangle A

Example

How many right angles does an equilateral triangle have?

1. 0

Answer: 0

Example

Lucia faces West and makes a three-quarter turn anticlockwise. Which direction is Lucia facing now?

1. North

Answer: North