Question

classify each triangle by each angles and sides.
7)
8)
9)
10)
11)
12)
classify each triangle by each angles and sides. equal sides and equal angles, if any, are indicated in each diagram.
13)
14)

Explanation:

Step1: Recall triangle - classification rules

Classify by angles (acute: all angles < 90°, right: one angle = 90°, obtuse: one angle > 90°) and by sides (equilateral: all sides equal, isosceles: two sides equal, scalene: no sides equal).

Step2: Analyze triangle 7

All angles are 60°, so it is an acute - angled triangle. All sides are 8.6, so it is an equilateral triangle.

Step3: Analyze triangle 8

Angles are 57°, 79°, 44°, all less than 90°, so it is an acute - angled triangle. Sides are 6.1, 8.7, 7.4, no two sides are equal, so it is a scalene triangle.

Step4: Analyze triangle 9

One angle is 90°, so it is a right - angled triangle. Sides are 11.2, 13.2, 7, no two sides are equal, so it is a scalene triangle.

Step5: Analyze triangle 10

One angle is 128° > 90°, so it is an obtuse - angled triangle. Sides are 2.5, 4.5, 2.5, two sides are equal, so it is an isosceles triangle.

Step6: Analyze triangle 11

All angles are less than 90°, so it is an acute - angled triangle. Sides are 3, 4.8, 4.8, two sides are equal, so it is an isosceles triangle.

Step7: Analyze triangle 12

One angle is 90°, so it is a right - angled triangle. Sides are 4.8, 4.8, 6.8, two sides are equal, so it is an isosceles triangle.

Step8: Analyze triangle 13

No information about angles and sides is given, so we cannot classify it.

Step9: Analyze triangle 14

No information about angles is given, but two sides are equal, so it is an isosceles triangle.

Answer:

1. Acute - angled, equilateral
2. Acute - angled, scalene
3. Right - angled, scalene
4. Obtuse - angled, isosceles
5. Acute - angled, isosceles
6. Right - angled, isosceles
7. Cannot be classified
8. Isosceles (angle - classification not possible with given info)