Mensuration and calculation common mistakes

Common mistakes

• Congruence and similarity calculations common mistake 1

  Writing a final answer without showing the method that justifies it. This can weaken answers for: [Higher only] Include relationships between lengths, areas and volumes in similar figures..

  Fix itShow the method first, then give the final answer in the required form. Apply this directly to Congruence and similarity calculations.

• Pythagoras and trigonometric ratios common mistake 1

  Writing a final answer without showing the method that justifies it. This can weaken answers for: [Foundation and Higher] Know and apply Pythagoras' theorem and the trigonometric ratios to find angles and lengths in right-angled triangles in two-dimensional figures..

  Fix itShow the method first, then give the final answer in the required form. Apply this directly to Pythagoras and trigonometric ratios. For Pythagoras, confirm the triangle is right-angled and identify the hypotenuse.

• Pythagoras and trigonometric ratios common mistake 1

  Writing a final answer without showing the method that justifies it. This can weaken answers for: [Higher only] Apply Pythagoras and trigonometric ratios to right-angled and general triangles in two and three dimensions where possible..

  Fix itShow the method first, then give the final answer in the required form. Apply this directly to Pythagoras and trigonometric ratios. For Pythagoras, confirm the triangle is right-angled and identify the hypotenuse.

• Exact trigonometric values common mistake 1

  Writing a final answer without showing the method that justifies it. This can weaken answers for: [Higher only] Know exact values of sin and cos for 0, 30, 45, 60 and 90 degrees..

  Fix itShow the method first, then give the final answer in the required form. Apply this directly to Exact trigonometric values.

• Exact trigonometric values common mistake 1

  Writing a final answer without showing the method that justifies it. This can weaken answers for: [Higher only] Know exact values of tan for 0, 30, 45 and 60 degrees..

  Fix itShow the method first, then give the final answer in the required form. Apply this directly to Exact trigonometric values.

• Sine and cosine rules common mistake 1

  Writing a final answer without showing the method that justifies it. This can weaken answers for: [Higher only] Know and apply the sine rule and cosine rule to find unknown lengths and angles..

  Fix itShow the method first, then give the final answer in the required form. Apply this directly to Sine and cosine rules.

• Area of any triangle common mistake 1

  Writing a final answer without showing the method that justifies it. This can weaken answers for: [Higher only] Know and apply Area = 1/2 ab sin C to calculate the area, sides or angles of any triangle..

  Fix itShow the method first, then give the final answer in the required form. Apply this directly to Area of any triangle.