A closed figure formed by three intersecting lines is called

The symbol for congruence is

Two circles are congruent.If the radius of one circle is 3cm, what is the radius of the other circle?

Two equilateral triangles are congruent when:

Two triangles are congruent, if any two pairs of angles and one pair of corresponding sides are equal. This rule is known as

Which congruence rule is used to show ΔACB ≅ ADB?

Given ΔOAP ≌ ΔOBP in figure, the criteria by which the triangles are congruent:

In figure, if AB = AC find x.

In ΔABC :

In ΔABC, ㄥB = 35°, ㄥC = 65° and the bisector of ㄥBAC meets BC in X.Then, the relation between BX and AX is

ABC is an isosceles triangle in which altitudes BE and CF are drawn to equal sides AC and AB respectively (see figure). Show that these altitudes are equal.

In ΔABC, if ㄥA = 50° and ㄥB = 60°, determine the shortest and the longest side of the triangle.

In a ΔDEF, if ㄥD = 30°, ㄥE = 60° then which side of the triangle is longest and which side is shortest?

In ΔABC, ㄥA = 60°, ㄥB = 40°, which side of this triangle is the smallest? Give reasons for your answer.

In ΔPQR, ㄥP = 100° and ㄥR = 60°, which side of the triangle is the longest. Give reasons for your answer.

ABCD is a quadrilateral in which AD = BC and \(\angle DAB=\angle CBA\) (see fihure).Prove that:

(i) \(\triangle ABD\cong \triangle BAC\)
(ii) BD = AC
(iii) \(\angle ABD=\angle BAC\)

AD and BC are equal perpendiculars to a line segment AB (see figure). Show that CD bisects AB.

In figure, AC = AE, AB = AD and \(\angle BAD=\angle EAC\). Show that BC = DE

Two sides AB and BC and median AM of one triangle ABC are respectively equal to sides PQ and QR and median PN of \(\angle PQR\) (see figure). Show that:
(i) \(\triangle ABM\cong \triangle PQN\) (ii) \(\triangle ABC\cong \triangle PQR\)

In figure, AB 丄 AE, BC 丄 AB, CE =DE and ㄥAED = 120°. Find
(a) ㄥ EDC
(b) ㄥDEC
(c) Hence prove that EDC is an equilateral triangle.

In the given figure ABCD is a square and M is the mid-point of AB. \(PQ\bot CM\) meets AD at P and CB produced at Q. Prove that PA = BQ.

In figure, it is given that RT = TS, \(\angle 1=2\angle 2\) and \(\angle 4=2\angle 3\) . Prove that
(i) \(\triangle RBT\cong \triangle SAT\)
(ii) RB = AS

In figure, ΔABD and ΔBCD are isosceles triangles on the same base BD. Prove that ㄥABC = ㄥADC.