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Geometry (FL B.E.S.T.)

Course: Geometry (FL B.E.S.T.) > Unit 5

Lesson 1: Theorems concerning triangle properties

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Prove triangle properties

CCSS.Math: HSG.CO.C.10, HSG.SRT.B.5

Google Classroom

Liliana tried to prove that M, N, equals, M, P in the following diagram.

Step	Statement	Reason
1	m, angle, M, N, P, equals, m, angle, M, P, N, equals, 65, degree	Given
2	Construct altitude M, Q.
3	m, angle, M, Q, N, equals, m, angle, M, Q, P, equals, 90, degree	Definition of altitude
4	triangle, M, Q, N, \cong, triangle, M, Q, P	Angle-angle-side congruence
5	M, N, equals, M, P	Corresponding sides of congruent figures have equal lengths.

What was the first mistake in Liliana's proof?

(Choice A)
m, angle, M, P, N was not given.
(Choice B)
Liliana failed to establish the conditions for the angle-angle-side criterion.
(Choice C)
The angle-angle-side criterion does not guarantee congruence.
(Choice D)
Sides start overline, M, N, end overline and start overline, M, P, end overline are not corresponding sides of congruent triangles.

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