The length of the base and the area of an isosceles triangle are respectively 8 cm and 12 cm². The length of each equal side is :
15 cm
10 cm
6 cm
5 cm
Mensuration
1 Like

Question

The length of the base and the area of an isosceles triangle are respectively 8 cm and 12 cm2. The length of each equal side is : 1. 15 cm 2. 10 cm 3. 6 cm 4. 5 cm

KnowledgeBoat · Accepted Answer

ABC is an isosceles triangle with AB = AC and base (BC) = 8 cm. Area of a triangle = × base × height Area of triangle ABC = × BC × AD ⇒ 12 = × 8 × AD ⇒ AD = = 3 cm. In an isosceles triangle, the perpendicular from the common vertex to the base, bisects the base. ∴ BD = DC = = 4 cm. In triangle ABD, ⇒ Hypotenuse2 = Base2 + Height2 ⇒ AB2 = BD2 + AD2 ⇒ AB2 = 42 + 32 ⇒ AB2 = 16 + 9 ⇒ AB2 = 25 ⇒ AB = ⇒ AB = 5 cm. ∴ AB = AC = 5 cm. Hence, option 4 is the correct option.

Mathematics

The length of the base and the area of an isosceles triangle are respectively 8 cm and 12 cm². The length of each equal side is :
15 cm
10 cm
6 cm
5 cm

Mensuration

Related Questions

The adjoining figure shows a field with the measurement given in metres. Find the area of the field.

The length of the base of an isosceles triangle is 24 cm and the length of each equal side is 13 cm. The area of the triangle is :
60 cm²
120 cm²
156 cm²
164 cm²

One side of a parallelogram is 6 m. If the area of a parallelogram is 30 m², then its height corresponding to the side is :
10 m
5 m
12 m
14 m