(on reassignment).
Plaintiff Jeanne Rosenberg (appellant) appeals from a judgment entered upon a jury verdict for defendants Richard Mosher and All American, Inc. (appellees).1 The trial court also denied appellant’s motions for a directed verdict, for judgment notwithstanding the verdict, and for a new trial. We reverse and remand.
Appellant brought this action to recover for personal injuries she received when ap-pellee Mosher, while driving a tractor/trailer rig owned by appellee All American, Inc., collided with a van owned by appellant and her former husband. At the time of the collision appellant was sleeping in the rear of the van which was being driven by a companion of appellant and her husband. The parties were driving across Iowa on *80interstate highway 80 in the early morning darkness when the collision occurred. Both vehicles were traveling east-bound when Mosher first saw the rear reflectors or taillights on the van approximately 100 feet ahead of him. Mosher swerved but was unable to avoid hitting the rear of the van. The evidence conflicted on the speed of appellants’ van and the working condition of its taillights. Mosher testified that oncoming vehicles could have been more than 600 feet from him at the location of the collision but he could not recall if he had met any oncoming vehicles at the point of the collision. He also stated his headlights had been on low beam because of earlier oncoming traffic.
Appellees initially moved to dismiss this appeal arguing that appellant’s notice of appeal was not timely filed after appellant made a motion for new trial upon which the trial court did not act within 20 days after the motion had been filed. See SDCL 15-6-59(b). In First National Bank of Beresford v. Nelson, 323 N.W.2d 879, we calculated the circuit court’s 20-day period to act on a motion for new trial from the date of “presentation” which we interpreted as the date of hearing. Calculating the twenty-day period from the date of hearing on the motion for new trial, and not from the date of filing as appellees calculate, we have determined that appellant’s notice of appeal was timely filed.
The jury was partially instructed on Iowa law regarding the lighting equipment that is required on vehicles. Appellant contends, however, that the trial court erroneously refused to instruct the jury on the law of Iowa which requires, (1) a driver to use enough light at certain times to reveal persons and vehicles at a safe distance ahead; and, (2) a vehicle to be equipped with headlights capable of revealing persons and vehicles for a distance of at least 350 feet ahead when on high beam.2
“A failure to give a requested instruction setting forth the applicable law constitutes prejudicial error, [cites omitted].” Atyeo v. Paulsen, 319 N.W.2d 164, 165 (S.D.1982); Miller v. Baken Park, Inc., 84 S.D. 624, 631,175 N.W.2d 605, 609 (1970), modified 85 S.D. 133, 178 N.W.2d 560 (1970).3 Appellant’s complaint did not precisely allege that appellees’ negligence included a failure to use enough light or to equip the tractor rig with the required lights. Appellant’s theory of negligence underlying her allegations fairly included these facts, however. Enough evidence was also presented to raise a fact question for the jury on whether the tractor was properly equipped with lights or whether the lights should have been on high beam. “The trial court has a duty to instruct the jury on applicable law where the theory [of liability] is supported by competent evi*81dence. [cites omitted].” Jahnig v. Coisman, 283 N.W.2d 557, 560 (S.D.1979). This the trial court failed to do.
Appellant also contends that the deposition of the Iowa highway patrolman who investigated the accident, particularly his testimony regarding the speed of the van, was erroneously read to the jury. The patrolman went so far as to admit that he could not remember where he came up with the estimate of the speed of Rosenberg’s van though he said the estimate may have been given by Mosher. The patrolman’s deposition testimony was hearsay to the extent that it was based on statements made by anyone other than the patrolman. SDCL 19-16-1(3). Appellees have not argued that portions of the deposition were not hearsay. Appellees have not argued that the testimony was within one of the hearsay exceptions. To the extent that the patrolman’s deposition testimony was hearsay it was inadmissible. SDCL 19-16 — 4.
The other issues raised by appellant are without merit.
The judgment is reversed and the case is remanded for a new trial consistent with this opinion.
FOSHEIM, C.J., and WOLLMAN and MORGAN, JJ., concur. HENDERSON, J., concurs in result.. Mrs. Rosenberg’s former husband was also a plaintiff but he has not appealed.
. Iowa Code § 321.409 (1966) requires vehicles to be equipped with headlamps subject to the following limitations relevant here:
1. There shall be an uppermost distribution of light, or composite beam, so aimed and of sufficient intensity to reveal persons and vehicles at a distance of at least three hundred fifty feet ahead for all conditions.
2. There shall be a lowermost distribution of light, or composite beam so aimed and of sufficient intensity to reveal persons and vehicles at a distance of at least one hundred feet ahead. On a straight level road under any condition of loading none of the high-intensity portion of the beam shall be directed to strike the eyes of an approaching driver.
The relevant portions of Iowa Code § 321.415 (1966) provide:
Whenever a motor vehicle is being operated on a roadway or shoulder [from sunset to sunrise], the driver shall use a distribution of Iight, or composite beam, directed high enough and of sufficient intensity to reveal persons and vehicles at a safe distance in advance of the vehicle, subject to the following requirements and limitations:
1. Whenever a driver of a vehicle approaches an oncoming vehicle within five hundred feet, the driver shall use a distribution of light, or composite beam, so aimed that the glaring rays are not projected into the eyes of the oncoming driver. The lowermost distribution of light, or composite beam, specified in section 321.409, subsection 2, shall be deemed to avoid glare at all times, regardless of road contour and loading.
. In Iowa, violation of safety statutes regulating the operation of motor vehicles is negligence as a matter of law. Berhow v. Kroack, 195 N.W.2d 379 (Iowa 1972); Kohler v. Sheffert, 250 Iowa 899, 96 N.W.2d 911 (1959)..