The following questions have three statements. Study the question and the statements and decide which of the statement(s) is/are necessary to answer the question. Find the area of the isosceles triangle. I: The length of median to the side opposite to the single largest angle in the triangle is 3√5 cm. II: The length of the side opposite to the single largest angle in the triangle is 12 cm. III: The perimeter of the triangle is 30 cm.

The following questions have three statements. Study the question and the statements and decide which of the statement(s) is/are necessary to answer the question. Find the area of the isosceles triangle. I: The length of median to the side opposite to the single largest angle in the triangle is 3√5 cm. II: The length of the side opposite to the single largest angle in the triangle is 12 cm. III: The perimeter of the triangle is 30 cm. Correct Answer Any two statements are sufficient to answer the question.

Statement I and II:

The length of median to the side opposite to the single largest angle in the triangle is 3√5 cm and the length of the side opposite to the single largest angle in the triangle is 12 cm;

Side opposite to the single largest angle will be longest.

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From the figure:

We can find the value of AB and AC using Pythagoras theorem.

∴The area of the triangle can be find out with help of lengths of all three sides.

Statement II and III:

The length of the side opposite to the single largest angle in the triangle is 12 cm and perimeter of the triangle is 30 cm;

∴ The equal sides of the triangle = (30 – 12)/2 = 9 cm

∴ The area of the triangle can be find out with help of lengths of all three sides.

Statement I and III:

AB + BC + AC = 30

⇒ 2AB + BC = 30

⇒ AB = (30 – BC)/2      ----(1)

Using Apollonius’ theorem

AB2 + AC2 = 2CD2 + 2AD2

⇒ 2AB2 = 2CD2 + 2AD2      (∵ ΔABC is isosceles triangle)

⇒ AB2 – (BC/2)2 = AD2      (∵ 2CD = BC)

⇒ (30 – BC)2 – BC2 = 4(3√5)2      {from eq. (1)}

⇒ 900 + BC2 – 60BC – BC2 = 180

⇒ BC = 12 cm

Area of triangle = 1/2 × BC × AD = 1/2 × 12 × 3√5

∴ Any two of the statements are sufficient to answer the question

Related Questions

The given question consists of three statements numbered I, II and III. You have to decide whether the data provided in the statements are sufficient to answer the question. Read all the statements and answer the question. What is the area of an isosceles triangle? I. Perimeter of isosceles triangle is 28 m. II. Base of the triangle is 18 m. III. Height of the triangle is 13 m.
The following question is accompanied by three statements (I), (II), and (III). You have to determine which statements(s) is/are sufficient/necessary to answer the questions. A triangle is circumscribed by a circle. What is the perimeter of the triangle? Statement I. The circumference of the circle is 14π cm. Statement II. The triangle is an isosceles triangle. Statement III. The largest side of the triangle is the diameter of the circle.