Question

classify the triangles by their sides and angles.

triangle
side name
angle name
a.
select
select
b.
select
select
c.
select
select
d.
select
select

Explanation:

Step1: Classify triangle by sides

• Scalene triangle: All sides are of different lengths. In triangle a, sides are \(11.2\), \(13.2\), \(7\).
• Isosceles triangle: Two sides are equal. In triangle b, two sides are \(2.5\). In triangle c, two sides are equal (marked with red lines).
• Equilateral triangle: All sides are equal. In triangle d, all sides are \(8.6\).

Step2: Classify triangle by angles

• Right - angled triangle: One angle is \(90^{\circ}\). In triangle a, one angle is \(90^{\circ}\).
• Obtuse - angled triangle: One angle is greater than \(90^{\circ}\). In triangle b, one angle is \(128^{\circ}\).
• Acute - angled triangle: All angles are less than \(90^{\circ}\). In triangle c, all angles are acute (as no angle is \(90^{\circ}\) or more). In triangle d, all angles are \(60^{\circ}\) (less than \(90^{\circ}\)).

Answer:

a. Scalene triangle, Right - angled triangle
b. Isosceles triangle, Obtuse - angled triangle
c. Isosceles triangle, Acute - angled triangle
d. Equilateral triangle, Acute - angled triangle