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
Each SEAG paper has 28 maths questions. Questions 29 to 50 are multiple choice with five possible answers, and questions 51 to 56 need a short written answer. With 56 questions in 60 minutes across English and maths, that is about a minute per question.
SEAGReady breaks area of triangles into 3 steps, taught in order so each skill builds on the last.
Find the area of a right-angled triangle as half the rectangle it comes from, using ½ × base × height (e.g., ½ × 8 cm × 6 cm = 24 cm²)
Find the area of any triangle using the perpendicular height, not the sloping side, in ½ × base × height
Use a triangle's area to answer a real-life question, such as how many seed packets or how much fabric is needed
Try three free questions from our area of triangles course. They start easy and get harder, so you can see where your child's confidence runs out. If they manage the last one without a hint, this topic is probably secure. If not, the steps above show where to start.
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?
The diagram shows a triangular road sign. Which measurements should be used to calculate its area, and what is the area?
The triangular field shown needs fencing at £5 per metre and grass seed at £2 per 100 m². What is the total cost?
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
The base is the bottom edge
base = 8 cm
Step 1 of 4
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?
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.
These are the misconceptions we see most often in area of triangles, including the ones our practice questions are specifically designed to catch.
Struggling with area of triangles? The real gap is often in one of these earlier topics.
Sitting the SEAG test this November? Read our last-month revision plan, Paper 1 vs Paper 2 and test day guide.
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.
Free to start · no card needed