Master P196 Check P211 Strengthen P213 Test P222 extend 8 Extend You will: • Extend your understanding with problem-solving. 1 These triangles are made using matches. A B C D What is the name of each triangle? Discussion Could you make an isosceles triangle using 10 matches? 2 Find as many polygons as you can in this image. Name each one and say if it looks regular. 3 a Draw a triangle with three different sides and three acute angles. Draw it big enough to measure the angles. b What kind of triangle have you drawn? c Measure the angles. What do you notice? d Repeat for a scalene triangle with an obtuse angle. e Repeat for another scalene triangle. f Copy and complete the sentence. The angles of a scalene triangle are __________ Q3a hint An acute angle is less than u°. Q3d hint An obtuse angle lies between u° and u°. 4 Reasoning Using centimetre squared paper a Draw a rectangle of length 3 cm and width 5 cm. Mark the equal sides using dashes. b Repeat part a but use a width of 4 cm. c Repeat using a width of 3 cm. What is another name for this rectangle? d Copy and complete the sentence. A square is also a ________ 5 Problem-solving The diagram shows the two flaps on the top of a cardboard box. Work out the perimeter of a the top of the box b one of the two flaps. 30 cm 40 cm Q5b hint The two flaps have the same length. Unit 8 Measuring and shapes 218