NCERT Exemplar Solutions
Class 7 - Mathematics - Unit 6: Triangles

True or False

In a triangle, sum of squares of two sides is equal to the square of the third side.

Sum of two sides of a triangle is greater than or equal to the third side.

The difference between the lengths of any two sides of a triangle is smaller than the length of third side.

In ΔABC, AB = 3.5 cm, AC = 5 cm, BC = 6 cm and in ΔPQR, PR = 3.5 cm, PQ = 5 cm, RQ = 6 cm. Then ΔABC ≅ ΔPQR.

Sum of any two angles of a triangle is always greater than the third angle.

The sum of the measures of three angles of a triangle is greater than 180°.

It is possible to have a right-angled equilateral triangle.

If M is the mid-point of a line segment AB, then we can say that AM and MB are congruent.

It is possible to have a triangle in which two of the angles are right angles.

It is possible to have a triangle in which two of the angles are obtuse.

It is possible to have a triangle in which two angles are acute.

It is possible to have a triangle in which each angle is less than 60°.

It is possible to have a triangle in which each angle is greater than 60°.

It is possible to have a triangle in which each angle is equal to 60°.

A right-angled triangle may have all sides equal.

If two angles of a triangle are equal, the third angle is also equal to each of the other two angles.

In Fig. 6.28, two triangles are congruent by RHS.

The congruent figures super impose each other completely.

A one rupee coin is congruent to a five rupee coin.

The top and bottom faces of a kaleidoscope are congruent.

Two acute angles are congruent.

Two right angles are congruent.

Two figures are congruent, if they have the same shape.

If the areas of two squares is same, they are congruent.

If the areas of two rectangles are same, they are congruent.

If the areas of two circles are the same, they are congruent.

Two squares having same perimeter are congruent.

Two circles having same circumference are congruent.

If three angles of two triangles are equal, triangles are congruent.

If two legs of a right triangle are equal to two legs of another right triangle, then the right triangles are congruent.

If two sides and one angle of a triangle are equal to the two sides and angle of another triangle, then the two triangles are congruent.

If two triangles are congruent, then the corresponding angles are equal.

If two angles and a side of a triangle are equal to two angles and a side of another triangle, then the triangles are congruent.

If the hypotenuse of one right triangle is equal to the hypotenuse of another right triangle, then the triangles are congruent.

If hypotenuse and an acute angle of one right triangle are equal to the hypotenuse and an acute angle of another right triangle, then the triangles are congruent.

AAS congruence criterion is same as ASA congruence criterion.

In Fig. 6.29, AD ⟂ BC and AD is the bisector of angle BAC. Then, ΔABD ≅ ΔACD by RHS.