Anja is creating a triangle using three straws. the two shorter straws have lengths of 20 cm and 21 cm. how long, in centimeters, should the third straw be for anja to create a right triangle?

length of third straw will be 29 cm.

step-by-step explanation:

anja has to create a triangle with three straws. two shorter sides are 20 cm and 21 cm long and we have to calculate the third side or third straw anja should use.

by pythagoras theorem

hypotenuse² = 20² + 21² = 400 + 441 = 841

hypotenuse = √841 = 29 cm

the result shows that third side should be 29 cm long to create a right angle triangle.

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.