Test: Angles and Constructions - Year 7 MCQ

A regular hexagon has 6 equal internal angles, and their sum is 720°. Each angle is 720° ÷ 6 = 120°. Thus, the correct answer is 120° (Option C).

The sum of interior angles in a triangle is 180°.
Given angles 35° and 55°, the third angle is 180° − (35° + 55°) = 180° − 90° = 90°.

An angle between 90° and 180° is called an obtuse angle, as it is wider than a right angle (90°) but less than a straight line (180°). Thus, the correct answer is obtuse angle.

A pentagon has 5 sides, and the sum of its interior angles is (5 − 2) × 180° = 540°. For a regular pentagon, each internal angle is 540° ÷ 5 = 108°. Thus, 108° × 5 = 540°, so the total is 540°.

An angle between 180° and 360° is called a reflex angle, as it is greater than a straight line (180°) but less than a full circle (360°). Thus, the correct answer is reflex angle.

Angles on a straight line sum to 180°, as a straight line represents a 180° angle (half a circle). Thus, the correct answer is 180°.

An obtuse angle measures between 90° and 180°. Among the options, 45° is acute, 90° is a right angle, 120° is obtuse, and 180° is a straight angle. Thus, 120° is the correct answer.

The sum of the interior angles of any triangle is always 180°. For example, in an equilateral triangle, each angle is 60° (3 × 60° = 180°), but this holds for all triangles. Thus, the correct answer is 180°.

To construct a right angle, draw a line segment, place the compass at one endpoint to draw an arc intersecting the segment, then use additional arcs to locate the midpoint and draw a perpendicular line, forming a 90° angle. Thus, the correct answer is Option B.

A scalene triangle has all sides of different lengths, whereas an equilateral triangle has all sides equal, and an isosceles triangle has at least two sides equal.