SEAGReady
MeasurementP7 level24 questions in the full course

Area of TrianglesSEAG Practice Questions

Calculating the area of triangles using the formula ½ × base × height.

Where your child meets this in real life: Calculating the area of a triangular garden bed or sail on a boat

What your child needs to know

SEAGReady breaks area of triangles into 3 steps, taught in order so each skill builds on the last.

  1. 1

    Right-Angled Triangles

    Master right-angled triangles skills

  2. 2

    Triangles with Perpendicular Height

    Master triangles with perpendicular height skills

  3. 3

    Word Problems

    Master word problems skills

Try these SEAG-style questions

Three free sample questions from our area of triangles course. Every question comes with a full explanation, and hints that guide without giving the answer away.

Question 1Confidence builder

The diagram shows a 10 cm by 6 cm rectangular card cut in half diagonally to make two identical triangular bookmarks. What is the area of each bookmark?

A 10 cm by 6 cm rectangle divided diagonally into two identical right-angled triangles.
Answer choices for question 1
Question 2Confidence builder

Rachel is painting the triangular warning sign shown. What is its area?

A triangular warning sign with a 40 cm base and a dashed 30 cm perpendicular height.
Answer choices for question 2
Question 3Confidence builder

Sophie wants to plant the triangular garden section shown. Each packet of flower seeds covers 10 m². How many packets does she need?

A triangular garden section with a 10 m base and a dashed 6 m perpendicular height.
Answer choices for question 3

Try the lesson: Right-Angled Triangles

This is the exact interactive worked example your child sees in SEAGReady. Step through it and watch the method build up.

Freya is cutting a rectangular piece of card in half diagonally to make two triangular bookmarks. The card is 8 cm along the bottom and 6 cm tall.

What is the area of each triangular bookmark?

½ × 8 × 6

Identify base and height
1

The base is the bottom edge

base = 8 cm

Step 1 of 4

Prefer to read? See every step written out

Freya is cutting a rectangular piece of card in half diagonally to make two triangular bookmarks. The card is 8 cm along the bottom and 6 cm tall.

What is the area of each triangular bookmark?

  1. 1

    Identify base and height

    • The base is the bottom edgebase = 8 cm
    • The height is perpendicular to the baseheight = 6 cm
  2. 2

    Apply the triangle area formula

    • Multiply base by height first8 × 6 = 48
    • Halve the answer (triangle is half a rectangle)48 ÷ 2 = 24 cm²

Each triangular bookmark has an area of 24 cm².

The key insight: A right-angled triangle is exactly half of a rectangle with the same base and height!

Common mix-up: 8 × 6 = 48 cm². Forgetting to halve gives you the rectangle area, not the triangle area.

Mistakes to watch for

These are the misconceptions we see most often in area of triangles, including the ones our practice questions are specifically designed to catch.

  • Forgetting to halve the answer
  • Using the slant side instead of the perpendicular height
  • Confusing base × height with perimeter

Build these skills first

Struggling with area of triangles? The real gap is often in one of these earlier topics.

Area of Rectangles

More measurement practice

Know Metric Unit NamesUnderstand Metric PrefixesConvert Length UnitsConvert Mass UnitsConvert Capacity UnitsConvert Units with Decimals
24 questions on this topic alone

Master area of triangles and everything it unlocks

SEAGReady finds the exact step where your child gets stuck, teaches it with worked examples like the one above, and brings it back for review so it sticks.

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Free to start · no card needed