Grade 4 · Math · Unit 13 of 16
Angles & Area
Acute, right, obtuse and area
What your child practises
Sorting angles into acute, right, obtuse and straight, finding area by multiplying length by width, and working backward to find a side.
Ontario Curriculum expectation: E2.4–E2.6 · classifying angles, area of rectangles, and finding a missing side from the area
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
A rectangle is 11 cm long and 3 cm wide. What is its area in square centimetres?
answer box
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33
Hint: Area = length × width.
Question 2
A rectangle has an area of 72 square centimetres. It is 12 cm long. How wide is it, in centimetres?
12 × = 72
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6
Hint: Divide the area by the length to find the width.
Question 3
A rectangle is 11 cm long and 7 cm wide. What is its area in square centimetres?
answer box
Show answer
77
Hint: Area = length × width.
Question 4
A straight line makes what kind of angle?
- right angle
- obtuse angle
- straight angle
Show answer
straight angle
Hint: It is flat, like half a turn.
Question 5
What kind of angle is this?
- acute
- right
- straight
- obtuse
Show answer
right
Hint: Acute is smaller than a square corner. Right is a square corner. Obtuse is bigger but not flat. Straight is flat.
Question 6
What kind of angle is this?
- acute
- right
- obtuse
- straight
Show answer
straight
Hint: Acute is smaller than a square corner. Right is a square corner. Obtuse is bigger but not flat. Straight is flat.