Question

In ΔCDE, the measure of ∠E=90°, the measure of ∠D=23°, and EC = 1.3 feet. Find the length of DE to the nearest tenth of a foot.

Answer 1

Answer: length of DE is about 3.3 ft

Step-by-step explanation:  A calculator is necessary!

DE is the unknown hypotenuse of the triangle

get the sine of 23° = 0.3907311285

Use the equation for sine

sin = o/h .

To find h,  Substitute values for sin and o.  O is EC, Opposite the 23° angle D

0.3907311285 = 1.3/h multiply both sides by h

h(0.3907311285) = 1.3 divide both sides by 0.3907311285

h = 1.3/0.3907311285

3.327096065 = h, the length of the hypotenuse, DE.