Triangles and quadrilaterals
Answers are for parents and teachers.
1
Name each triangle by its sides: (a) 5 cm, 5 cm, 8 cm; (b) 7 cm, 7 cm, 7 cm; (c) 4 cm, 5 cm, 6 cm.
(a) isosceles, (b) equilateral, (c) scalene.
2
A triangle has one obtuse angle. Can it be equilateral? Explain.
No. An equilateral triangle has three acute angles, so it cannot have an obtuse one.
3
On squared paper (1 square = 1 cm) draw a right triangle with legs of 6 cm and 8 cm. Measure the longest side with a ruler. Is the triangle scalene?
The longest side is 10 cm long. The sides 6, 8 and 10 are all different, so it is scalene (a right scalene triangle).
4
Name the quadrilateral: (a) four right angles, opposite sides equal but not all four equal; (b) exactly one pair of parallel sides; (c) four equal sides, no right angles.
(a) rectangle, (b) trapezoid, (c) rhombus.
5
Name one object at home for each shape: rectangle, rhombus and trapezoid. Draw one of them.
For example: a door (rectangle), a diamond-shaped tile (rhombus), the side of a bucket or a lampshade (trapezoid).