An isosceles triangle has an apex angle of . What is each base angle?
Answer and explanation
Correct answer: D. 70°
- Step 1: Angles in a triangle add up to , so the two base angles total .
- Step 2: The base angles are equal: .
Answer
70°.
Why not the others: 140°: This is the total of both base angles. 40°: This is the apex angle itself. 100°: This subtracts from instead of halving.
Practise more Geometry and Measures.
Free questions with an explanation for every one, and full timed GCSE English and Maths Resits (Grade 4) mock tests.
More Geometry and Measures questions
- What is the size of one interior angle of a regular octagon?
- What is the total surface area of a cuboid measuring cm by cm by cm?
- The bearing of town from town is . What is the bearing of from ?
- An isosceles triangle has two sides of cm and a base of cm. What is its area?
- A ladder m long leans against a vertical wall. Its foot is m from the wall. How high up the wall does it reach?
- The point is translated by the vector . What are the coordinates of its image?