Revision Quiz: Angles and Types of Triangles GCSE

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Learn GCSE triangle basics: classify triangles, use side and angle rules, and check if three lengths can form a triangle using the triangle inequality.

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Fascinating Fact:

For a bridge truss, the triangle inequality says any two sides together must be longer than the third. Sides 4, 7, 12 fail because 4 + 7 = 11 which is less than 12.

In GCSE Maths (Foundation), triangles appear everywhere. You will classify triangles by sides and angles, apply the triangle inequality, use interior angle sums (180°), and reason about isosceles and right-angled triangles in diagrams and problems.

Key Terms

Triangle inequality: In any triangle, the sum of any two side lengths must be greater than the remaining side.
Isosceles triangle: A triangle with two equal sides and two equal base angles.
Interior angles: The angles inside a polygon; for triangles these add to 180°.

Frequently Asked Questions (Click to see answers)

How can I tell if three lengths make a triangle?

Check the triangle inequality for all pairs. For lengths a, b, c: a + b > c, a + c > b, and b + c > a. If any fails, no triangle forms.

What do the angles in a triangle add up to?

The interior angles of any triangle sum to 180°. Knowing two angles lets you find the third by subtraction from 180°.

How do I classify triangles by sides and angles?

By sides: equilateral (three equal), isosceles (two equal), scalene (none equal). By angles: acute (all < 90°), right-angled (one 90°), obtuse (one > 90°).

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Maths Quiz - Triangles (F) (Questions)

Fascinating Fact:

Key Terms

Frequently Asked Questions (Click to see answers)

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