Year 11
Higher
Year 11
Higher

Prove triangles are congruent

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Lesson details

Key learning points

  1. In this lesson, we will learn how to prove that two triangles are congruent. We will investigate four different conditions involving observation and comparison of the angles and sides of each triangle. If any condition is met, we can determine that the triangles are congruent.

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3 Questions

Q1.
An image in a quiz
A
B
Correct answer: C
D
Q2.
An image in a quiz
A
Correct answer: B
Correct answer: C
D
Q3.
An image in a quiz
Correct answer: A
B
C
D

3 Questions

Q1.
ABCD is a parallelogram. Select the working that proves triangles ABC and BCD are congruent using the SSS conditions. Choose all that apply.
An image in a quiz
Correct answer: BD is a shared side
Opposite angles in a parallelogram are equal
Correct answer: Opposite lengths in a parallelogram are equal
Opposite lengths in a parallelogram are parallel
Q2.
ABCD is a parallelogram. Select the working that proves triangles ABC and BCD are congruent using the ASA conditions. Choose all that apply
An image in a quiz
∠ABD = ∠BDC and ∠ADB = ∠DBC as alternate angles are equal. AD = BC (opposite angles equal)
Correct answer: ∠ABD = ∠BDC and ∠ADB = ∠DBC as alternate angles are equal. BD is a shared side.
AB = DC and AD = BC as opposite lengths in a parallelogram are equal. ∠DAB = ∠BCD
BD is a shared side. AB = DC. ∠ABD = ∠BDC as alternate angles are equal.
Q3.
ABCD is a parallelogram. Select the working that proves triangles ABC and BCD are congruent using the SAS conditions. Choose all that apply.
An image in a quiz
∠ABD = ∠BDC and ∠ADB = ∠DBC as alternate angles are equal. AD=BC.
∠ABD = ∠BDC and ∠ADB=∠DBC as alternate angles are equal. BD is a shared side.
Correct answer: AB=DC and AD=BC and ∠DAB = ∠BCD (opposite lengths in a parallelogram are equal)
Correct answer: BD is a shared side. AB=DC. ∠ABD=∠BDC as alternate angles are equal.