Edexcel IGCSE Math B 1.J Upper & lower bounds Question Bank

[UB =] 5.25 or [LB =] 5.15
B1 a correct upper or lower bound seen or used. Allow
[U B / 2=] 2.625 or [L B / 2=] 2.575(86)=h/UB / 2 or (4)=UB / 2/h or h/ (86)=UB / 2/ (4)(86)=UB / 2/S or (90-86[=4])=UB / 2/S or S/ (86)=UB/ 8 or

5.25^2=S^2+S^2-2 S^2 8

M1 for setting up an equation to find the height of the triangle ( h ) or side length ( S )

allow 5.1 \\leqslant UB \\leqslant 5.3 or 2.55 \\leqslant U B / 2 \\leqslant 2.65

condone if use 171.5 \\leqslant angle \\leqslant 172.5h=UB / 2 (86)[=37.539 ] or h=UB / 2/ (4) or h=UB / 2/ (4) x (86)S=UB / 2/ (86)[=37.63 ] or S=UB / 2/ (90-86)[=37.63] or S=UB/ (8) x (86)

or S=5.25^22-2 (8)

M1 for correct method to find h or S

Allow 5.1 \\leqslant UB \\leqslant 5.3 or 2.55 \\leqslant U B / 2 \\leqslant 2.65 or awrt 37.5 or awrt 37.6

If previous method mark is awarded allow for awrt 36.5 \\leqslant h \\leqslant awrt 37.9 or awrt 36.5 \\leqslant S \\leqslant awrt 40.0

This mark implies the previous M1

Area of triangle =1/2 x U B x " h "[ Area =98.54 ] or 1/2 x " h^ x " S " x (4)
or 1/2 x U B x " S " x (86) or 1/2 x " S " x " S " (8)

M1 for finding the area of the triangle

where 5.1 \\leqslant UB \\leqslant 5.3 and S<5 or S>5.5 or h<5 or h>5.5 allow awrt 98.5

NB 0.5 x UB x UB 172 is M0

or R=UB+UB+S2 and R(R-UB)(R-UB)(R-S)}

Area of polygon = " 45 " x " 98.54 or 2 x " 45 " x " 49.27 "

M1 dep on the 3^rd M mark being awarded

4430

A1dep on seeing 5.25or 2.625 for UB throughout awrt 4430