smc-5008-10-Classifying

Properties of Geometrical Figures, SM-Bank 003 MC

Tom drew this shape on grid paper.

Which one of the shapes below when joined to Tom's shape without an overlap, will not make isosceles triangle?

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\(C\)

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\(\text{An isosceles triangle has two sides of the same length.}\)

\(\text{Option C will form a scalene triangle (all sides different lengths).}\)

\(\Rightarrow C\)

Which statement about the triangle pictured above is correct?

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`C`

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`text(The third angle of the triangle)\ = 180-(60+60) = 60°`

`:.\ text(It is an equilateral triangle.)`

`=>C`

Which one of these is a right-angled isosceles triangle?

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\(D\)

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\(\text{Isosceles triangle had 2 sides the same length.}\)

\(\text{Right-angled triangle has one angle equal to 90°.}\)

\(\text{Unknown angle}\)	\(= 180-(45 + 45)\)
	\(= 90^{\circ}\)

\(\Rightarrow D\)

Which one of the following triangles is impossible to draw?

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`D`

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`text(A right angle = 90°.)`

`text{Since an obtuse angle is greater than 90°, it is impossible for}`

`text(a triangle, with an angle sum less than 180°, to have both.)`

`=>D`

A triangle has two acute angles.

What type of angle couldn't the third angle be?

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`D`

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`text(A triangle’s angles add up to 180°, and a reflex angle is)`

`text(greater than 180°.)`

`:.\ text(The third angle cannot be reflex.)`

`=>D`